Photochromic intraocular lenses with advanced polymerization control

Abstract

A phototunable lens (LAL) is described that suppresses unintended light power fluctuations. These LALs comprise a polymer silicone network implanted with a mobile macromer, a non-switchable UV absorber, and a photoinitiator, and a front protective layer containing a switchable UV absorber. The LAL is phototunable by molding irradiation, which activates a photoinitiator that induces polymerization of the mobile macromer, thereby changing the light power of the LAL. The LAL can accommodate oxygen concentrations of 0.5 to 20 ppm, and the ratio of oxygen concentration multiplied by the oxygen-driven photoinitiator quenching rate to the mobile macromer concentration multiplied by the photoinitiator-driven polymerization addition rate is greater than 10. Some of these LALs include a non-switchable UV absorber, or a radical scavenger, or a monofunctional or sterically hindered mobile macromer, or a switchable photoinitiator, or an immobilized photoinitiator in the front protective layer.

Description

[Technical Field] 【0001】 Cross-reference of related applications This application claims the interests of U.S. Provisional Application No. 63 / 505,988 filed 2 June 2023, which is incorporated herein by whole reference, and U.S. Application No. 18 / 678,723, filed 30 May 2024, “Light adjustable intraocular lenses with advanced polymerization control,” by I. Goldshleger, J. Kondis, V. Piunova, and C. Sandstedt. This invention relates to light-adjustable lenses, and more particularly to advanced control techniques for the polymerization process in these lenses. [Background technology] 【0002】 Cataract surgery techniques are advancing at a remarkable pace. Generations of phacoemulsification platforms and, more recently, the introduction of surgical lasers continue to improve the precision of intraocular lens (IOL) placement and reduce unintended medical outcomes. Nevertheless, after IOL implantation, the postoperative healing process can cause the IOL to shift or tilt in a significant percentage of patients, leading to decreased vision and deviations from the planned surgical outcome. Recently, new techniques have been developed to correct or mitigate such postoperative displacement or tilting of IOLs. IOLs may be fabricated from photopolymerizable materials, hereafter referred to as photoadjustable lenses or LALs. In the first few days after surgery, implanted LALs may shift and tilt, eventually settling in a postoperative position different from that planned by the surgeon, just like all other intraocular lenses or IOLs. However, unlike other IOLs, once the LAL has settled, a light delivery system (LDD) can be used to irradiate the LAL with an irradiation beam profile that induces photopolymerization in a predetermined spatial profile, thereby altering the refractive properties of the LAL. This change in refraction adjusts the optical performance of the LAL, correcting any unintended postoperative displacement or tilting of the LAL. This adjustment procedure is followed by a lock-in procedure, the function of which is to deactivate all remaining photopolymerizable material. In limited cases, the lock-in procedure may not deactivate all photopolymerizable materials. Subsequently, exposure of the remaining photopolymerizable material to sunlight can cause further undesirable fluctuations in the optical power of the LAL. Therefore, advanced polymerization control techniques are needed to limit or eliminate these undesirable optical power fluctuations of the LAL. [Overview of the Initiative] 【0003】 Light-adjustable lenses (LALs) that address the above challenges may include various polymer-controlled designs, processes, and technologies, as described below. Some light-tunable lenses (LALs) comprise a polymer silicone network injected with a mobile macromer, a non-switchable UV absorber, and a photoinitiator, and a front protective layer containing a switchable UV absorber. The LAL is light-tunable by molding irradiation, which activates the photoinitiator that induces polymerization of the mobile macromer, thereby changing the light power of the LAL. The LAL can accommodate oxygen concentrations in the range of 0.5 to 20 ppm, and the ratio R of the oxygen concentration [O2] multiplied by the oxygen-driven photoinitiator quenching rate kq, R = kq[O2] / ka[MM], to the mobile macromer concentration [MM] multiplied by the photoinitiator-driven polymerization addition rate ka, is greater than 10. In some light-adjustable lenses, the front protective layer includes a non-switchable UV absorber. In some light-adjustable lenses, LAL contains radical scavengers or antioxidants. In some light-adjustable lenses, the mobile macromer is monofunctional. In some light-adjustable lenses, the mobile macromer is sterically hindered. 【0004】 In some photo-adjustable lenses, the photoinitiator can be switched between a protected state and an activatable state. In some phototunable lenses, the chemical composition, concentration, and reaction rate of the silicone network, mobile macromer, switchable and non-switchable UV absorbers, and photoinitiators are such that the slope of the time-dependent power adjustment curve more than doubles after time t(activate) during the phototuning procedure, with t(activate) ranging from 3 to 100 seconds. In some light-tunable lenses, the photoinitiator is immobilized on a polymer silicone network. 【0005】 In some light-tunable lenses, the photoinitiator can become an activated photoinitiator upon absorbing UV photons, and the activated photoinitiator can activate the mobile macromer by activating the terminal groups of the mobile macromer. In some light-adjustable lenses, the active terminal group of a mobile macromer can form a bond with a second mobile macromer, thereby activating the terminal group of the second mobile macromer. In some light-adjustable lenses, a reaction between an activated photoinitiator and oxygen generates a low-activity photoinitiator derivative. In some light-adjustable lenses, a low-activity compound is produced by the reaction of an activated mobile macromer with oxygen, and LAL contains a radical scavenger that can react with the low-activity compound to convert it into an inactive compound. [Brief explanation of the drawing] 【0006】 [Figure 1A-1C] This diagram shows the steps of light adjustment in a light-adjustable lens (LAL100). [Figure 1D-1F] This diagram shows the steps of light adjustment in a light-adjustable lens (LAL100). [Figure 2A] This figure shows a light-adjustable lens (LAL) having a front protective layer and a back protective layer. [Figure 2B] This figure shows a light-adjustable lens (LAL) having a front protective layer and a back protective layer. [Figure 3] This figure shows the main compounds and structures in LAL100. [Figure 4] This diagram shows the steps of the photo-induced interaction between a mobile macromer and a photoinitiator. [Figure 5A] This figure shows two paths for immobilizing mobile macromers. [Figure 5B] This figure shows two paths for immobilizing mobile macromers. [Figure 5C] This figure shows two paths for immobilizing mobile macromers. [Figure 6A] This figure shows the dynamics of oxygen concentration and power changes during UV irradiation. [Figure 6B] This figure shows the dynamics of oxygen concentration and power changes during UV irradiation. [Figure 7] A diagram showing the concentrations of oxygen [O2] and photoinitiator radicals [PI*] during and after a UV irradiation procedure including adjustment, lock-in and possibly zone formation. [Figure 8] A diagram showing the concentrations of oxygen [O2] and photoinitiator radicals [PI*] during and after unintentional UV exposure. [Figure 9A] A diagram showing the reaction kinetics of radical scavenger RS 125. [Figure 9B] A diagram showing the reaction kinetics of radical scavenger RS 125. [Figure 10A] A diagram summarizing the steps of polymerization and the polymerization control design process. [Figure 10B] A diagram summarizing the steps of polymerization and the polymerization control design process. [Figure 11A] A diagram showing the concentrations of oxygen [O2] and XOO* radicals [XOO*] in the absence and presence of radical scavenger RS. [Figure 11B] A diagram showing the concentrations of oxygen [O2] and XOO* radicals [XOO*] in the absence and presence of radical scavenger RS. [Figure 12] A diagram showing the polymerization using monofunctional macromer MM(1). [Figure 13] A diagram showing the absorption characteristics of switchable and non-switchable UV absorbers. 【Modes for Carrying Out the Invention】 【0007】 The central step in cataract surgery is the implantation of an intraocular lens (IOL). The ophthalmologist selects an IOL with optimal optical properties using sophisticated, time-validated calculations and positions it very carefully within the capsule. After implantation, the IOL settles within the eye as the wound and incision heals and the eye tissue responds to the surgery and implantation. This usually takes several weeks, and it is common for the IOL to shift and / or tilt from its implanted position. Therefore, despite careful preparation and informed selection by the ophthalmologist, such shifting and tilting can cause the IOL's focus to move away from the retina, resulting in decreased visual acuity. Because conventional IOLs have a fixed shape and optical properties, patients must live with this reduced vision, for example, by wearing corrective glasses. Some ophthalmologists perform LASIK surgery to correct such unintended shifts. In contrast, if a photochromic lens, or LAL100, is implanted in the patient's eye, once the LAL100 is established, the ophthalmologist can determine how to adjust the shape of the LAL100 to correct its misalignment and tilt. This adjustment is achieved by irradiating the LAL100 with a UV beam selected so that the beam profile achieves this shape adjustment. 【0008】 Figures 1A-F demonstrate that LAL100 is capable of such shape changes because its silicone polymer network is injected with (1) photoinitiator molecules that can be activated by an incoming UV irradiation beam, and (2) mobile macromers that can induce the activated photoinitiators to bind to or from the polymer network. Once bound to the network, the mobile macromers become immobile. This creates a chemical potential difference among the remaining mobile macromers, which forces them to diffuse from the high-concentration peripheral region to the central region where the concentration is depleted by photo-induced immobilization polymerization. This diffusion or influx of mobile macromers into the centrally irradiated region causes swelling of LAL100, thereby modifying its optical properties and re-optimizing the patient's vision. This chemistry of LAL100 will be explained in more detail shortly. Once the adjustment is performed, the remaining photoinitiators and mobile macromers are inactivated by a subsequent "lock-in" procedure, where "lock-in" UV radiation is applied at an intensity high enough to consume all, or essentially all, of them. 【0009】 To ensure that all photoactivatable compounds are actually deactivated, it is common to perform two lock-in procedures several days apart. However, requiring patients to return to the clinic for two lock-in procedures after the initial implantation and subsequent adjustment of the photopower imposes a significant burden on both the patient and the physician. Therefore, modifying the chemistry of these phototunable lenses to reduce the number of required lock-in procedures from two to one would greatly improve the overall convenience and acceptability of phototunable lens technology, effectively bringing its medical benefits to a much larger number of patients. However, it is still important that the modified lens chemistry ensures that the single lock-in procedure essentially consumes all photoactivatable compounds, allowing for sufficient stabilization of the lens and thus preventing any unintended photo-induced variations in any subsequent optical properties. 【0010】 Because the retina is highly sensitive to UV irradiation, the first generation LAL100 included UV absorbers distributed in its bulk and a strong UV-absorbing back layer. These UV absorbers already prevented retinal damage from accommodation and lock-in UV irradiation. As a further safety measure, patients are instructed to wear UV-blocking sunglasses from implantation to lock-in to prevent the UV content of sunlight from inducing unintended optical accommodation of the LAL100. Figures 2A-B show that recent improvements to the LAL100 have introduced an additional front protective layer 110. Figure 2A is a top view of these improved LAL100s, which also shows that the LAL100 is stabilized within the ocular lens capsule after implantation with the help of haptics 100h. Figure 2B is a side view of the LAL100 showing the novel front protective layer 110 and the previous back protective layer 120. This front protective layer 110 includes a switchable UV absorber that can switch between a strong UV absorption configuration and a weak UV absorption configuration. Such a switchable front protective layer 110 may provide good UV protection in its strong absorption configuration to prevent unintended optical accommodation before lock-in, while being switched to its weak absorption configuration to allow UV light to enter the LAL100 during the accommodation and lock-in procedure. Its chemistry will be detailed later. These improved lenses have been widely implanted in patients and, after two lock-in procedures, show no perceptible changes in optical properties and exhibit completely satisfactory optical stability. 【0011】 In the process of exploring the chemistry of one-lock-in lenses, laboratory experiments have shown that one-lock-in lenses may face potential challenges in rare circumstances. Some of these challenges are referred to as “zone formation” and “power fluctuation,” both of which lead to undesirable changes in the optical power of LAL100 outside of the adjustment or lock-in procedure. As detailed below, these undesirable changes in optical power can be induced by at least two classes of processes. Faster, zone formation changes can be induced between the implantation and lock-in of LAL100, primarily by the UV component of ambient / natural light, when LAL100 still contains substantial amounts of photoinitiator and mobile macromer. Zone formation can be caused by relatively short-term UV exposure, examples of which may be a patient inadvertently looking at the sun without necessary sunglasses, perhaps during outdoor sports, or using a UV tanning bed. 【0012】 Another class of power variation processes, power fluctuations, are driven primarily by chemical reactions initiated by low-intensity ambient UV light but sustained by spontaneous chemical reactions that proceed without further UV irradiation. These self-sustaining power fluctuations occur much more slowly but may continue over long periods, perhaps even more slowly, after the initial lock-in process. As mentioned, the new generation LAL100 has an additional switchable front protective layer 110 whose primary function is to protect against zone formation. This front protective layer 110 may eliminate the need to wear sunglasses between implantation and lock-in, which is a clear advantage. However, this same front protective layer 110 also hinders the consumption of macromers and photoinitiators during the lock-in process. Therefore, a few percent of macromers and photoinitiators may remain activatable after the initial lock-in, thus maintaining chemical reactions that lead to power fluctuations. Furthermore, the switchable front protective layer 110 and the distributed UV absorbers still allow a very low percentage of UV photons to enter the bulk of the LAL100. Some of these UV photons may be absorbed by the remaining activatable photoinitiator in the central exposure region. This UV absorption by the activatable photoinitiator can initiate further self-sustaining chemical reactions, primarily unintended polymerization. Both of these mechanisms contribute to the slow power fluctuations of LAL100's optical power. Realistic ambient light exposure experiments using a single lock-in experimental lens demonstrated the possibility of such power fluctuations of approximately 0.1D–0.2D over several hundred hours after single lock-in. 【0013】 In response to the above challenges, this application primarily describes chemical considerations and designs for suppressing and minimizing this long-term, gradual power fluctuation in a new generation LAL100, with the ultimate goal of creating an optically stable, single-lock-in optically tunable lens. Furthermore, it should be noted that lens chemistry that reduces prolonged power fluctuations caused by self-sustaining, unintended polymerization after initial lock-in can also reduce short-term zone formation before initial lock-in. Preventing short-term zone formation with such novel lens chemistry eliminates the need to require patients to wear sunglasses until initial lock-in, thereby improving outcome control, patient comfort, and the acceptability of photochromic lens technology, and thus providing medical benefits to a larger number of patients. 【0014】 To prepare for this, the chemistry of the photo-tunable lens will now be described in more detail. LAL100 is formed from two polymerizable formulations: a silicone lens matrix or network formulation, and a photoreactive formulation. Much detail of these formulations is described by reference in its entirety in Jethmalani et al., US6,450,642, entitled "Lenses capable of post-fabrication power modification". In some embodiments, the silicone lens matrix is ​​a silicone polymer, e.g., vinyl-capsiloxane copolymer, and more specifically, divinylpolydimethyldiphenylsiloxane copolymer as shown: 【0015】 [ka] (wherein the formula, n and m may be in the range of 2 to 100, and in some embodiments, in the range of 2 to 30) may be included. The composition or concentration of this silicone copolymer may be in the range of 20% to 70%, and in some cases, in the range of 30% to 60%. 【0016】 Other components of the network formulation may be a wide variety of polyvinyl-functionalized silicone resins. An example is shown here: [ka] (In the formula, x and y may be in the range of 2 to 100, and in some embodiments, in the range of 2 to 30. The composition of this silicone resin may be in the range of 10% to 50%, and in some cases, in the range of 20% to 40%.) 【0017】 These two components can be linked to the silicone lens network 101 using various crosslinking agents XLK102, such as polyhydrosilane functional groups, as shown here: [ka] 【0018】 The composition of the crosslinking agent XLK102 may range from 1% to 10%, and in some cases from 3% to 7%. These crosslinking agents XLK102 can link siloxane polymers to each other into a silicone network 101 by a catalyst-assisted hydrosilylation polymerization process as part of the curing process. Curing is carried out at low temperatures to ensure that the photoreactive formulation maintains its photoreactivity. This polymerization process generates the large interconnected silicone network 101 or matrix, which was briefly described earlier. This polymer network 101 is immobile due to its enormous size and the fact that its numerous branches hinder its mobility. This forms the main chain of LAL100 and largely determines its mechanical and optical properties. 【0019】 The photoreactive formulation may contain various acrylate-terminated capsiloxane macromers, an example being the indicated polydimethylsiloxane having a methacrylate-terminated group: [ka] (wherein n and x are in the range of 2 to 100, and in some cases in the range of 2 to 30). These macromers are often shorter than the siloxane copolymers and silicone resins described above, are not anchored to the silicon network 101, and are therefore mobile. The composition of these mobile macromers may be in the range of 20% to 50%, and in some cases in the range of 30% to 40%. Importantly, the methacrylate end groups are photoactivatable via their activatable end groups (or end caps) 103, as further described below. These macromers are also affected by the curing process, but only partially. Some of them, via one of the methacrylate end caps 103, anchor to the crosslinking agent XLK 102 during the hydrosilylation process of curing, and thus become immobilized macromers themselves. At the same time, the other methacrylate end groups 103 of these immobilized macromers retain their photoactivity. The rest of these macromers remain unanchored to the network 101 and are therefore mobile. These are referred to as mobile macromers 104 or MM104. The macromer linked to the crosslinking agent is referred to as (a type of) immobilized macromer 105 or IM105. Figure 3 shows the obtained structure of the polymerized silicone network 101 in which IM105 is linked to the crosslinking agent XLK102 and MM104 remains mobile. 【0020】 The photoinitiator 106, or PI106, may be a wide variety of known photoinitiators. Some embodiments of the photoinitiator have a general formula or structure: [ka] The formula includes x-alkylbenzoin having (wherein R3 is H, an alkyl radical, an aryl radical, a substituted alkyl, or a substituted aryl radical; R4 is H, an alkyl radical, an aryl radical, a substituted alkyl, or a substituted aryl radical; and R5 and R6 are phenyl, or a substituted phenylallyl or allyloxy). Specific examples of R3 and R4 groups include methyl, phenyltrifluoropropyl, ethyl, and cyanopropyl. Examples of phenyl substituents on R5 and R6 groups include alkyl, alkoxy, halogen, alkaryl, cyanoalkyl, haloalkyl, and N,N-dialkylamino. 【0021】 Furthermore, photoinitiators 106 having one or more UV initiators bonded to a short polymer backbone or segment are also useful. These photoinitiators 106 have the general formula: AB-A1 (wherein A and A1 may be the same or different UV initiators, and B is a short polymer segment containing 2 to 28 monomer moieties). Generally, photoinitiators 106 tend to have the same polymer backbone as those used in the LAL100 network. For example, in the case of LAL100 made from a silicone polymer, the short polymer linking the initiators may also be a silicone polymer. Similarly, if LAL100 is polyacrylate-based, the short polymer chain may be polyacrylate. 【0022】 In one embodiment, the photoinitiator 106 is bonded to a polysiloxane crosslink and has the general formula: [ka] It comprises one or more UV initiators having the following characteristics. In the formula, R7 to R11 are independently selected from the group consisting of hydrogen, alkyl (primary, secondary, tertiary, cyclo), aryl, or heteroaryl moieties, n is an integer from 2 to 28, and at least one moiety R7 to R11 is a UV initiator. In preferred embodiments, R7 to R11 are most preferably methyl C1-C10 alkyl or phenyl, but at least one may be hydrogen. 【0023】 Particularly useful photoinitiators 106 include benzoyl peroxide (left) and benzoin (right): [ka] These are some examples. The incoming UV photons break down or cleave the central OO bond of benzoyl peroxide and the central CC bond of benzoin. A particularly useful photoinitiator 106 is BL4B, which contains benzoyl as shown. "L4" codes for four repeated silicone dimethyl units. [ka] 【0024】 BL4B PI 106 is bifunctional in the sense that it has two photocleavable bonds, indicated by two ellipses. Generally, when PI106 absorbs UV photons, it often decomposes or cleaves into two highly reactive radicals. The probability of this process is called the quantum yield. BL4B decomposes into a group with a benzoyl radical and a ketyl radical at its terminus, as shown below. Each of these radicals has an electron in a radical center, in a highly reactive state. These preparations allow us to describe photoactivated polymerization using chemical equations at a symbolic level, as well as specific examples. Following widely used notation, UV photons are denoted by hν, which represents their frequency ν multiplied by Planck's constant h. The number "365" next to hν indicates the approximate wavelength in nanometers of the photon most effective in performing this cleavage. Photons with wavelengths in the 10-20 nm range around 365 nm can also be used. Electrons in a highly reactive state, radical centers, are indicated by *, and compounds converted to radicals by these electrons are also indicated by *. The figure below shows the process of photocleavage of BL4B photoinitiator 106 into two radicals (step (1)): [ka] 【0025】 Figure 4 shows the photoactivation polymerization process in three steps at a symbolic level. Step (1) is the aforementioned photocleavage: the incident photon cleaves PI106 into two groups. (Symbolic representations of the corresponding chemical reactions use equations with an "s" appended: equation (1s) is a symbolic representation of the reaction in equation (1), for example): PI + hν = 2PI * (1 s) Both PI groups are activated in the sense that they are excited to a highly reactive state and therefore have electrons that form radicals, and for simplicity, both are denoted by PI*106*. The heterogeneous sizes of the two squares in Figure 4 capture the heterogeneous sizes of the two groups. 【0026】 Step (2) shows that each activated PI*106* group can react with MM104, and this reaction activates MM in the sense that it moves a highly reactive electronic state to the terminal group of MM and converts it into a radical. The complete reaction is shown below (Step (2)): [ka] 【0027】 The highly reactive electrons at the radical center of PI*106* break the double bond between the central carbon atom of the methacrylate terminal group and CH2 in this process. The electrons of the CH2 group form a bond with the radical center of PI*106*, deactivating PI*106*. dIt is deactivated to 106d (shown in shaded area) and bonded to MM104. Notably, the same reaction promotes the other electrons from the double bond to a highly reactive state, forming a new radical center on the central carbon. Figure 4 shows these processes in step (2) by symbols. The methacrylate terminal group 103 of MM104, whose double bond has been broken and one of its electrons promoted to a highly reactive state, is referred to as "radical X*", "activated radical X*", or "activated terminal group 103*". In the figure, open symbols indicate the group before the reaction (activatable terminal group 103, PI106), solid symbols indicate the activating group (activated radical X*103*, activated PI*106*), and shaded symbols indicate the deactivating group (inactivated terminal group (Xd)103d, inactivated PId 106d). The terminal group 103, which is converted to the radical X*, activates MM104 to activated MM*104*, and the activated radical may also be explicitly shown as MM-X*. The above reaction can be represented symbolically as (step (2)): PI*+MM=MM*-PId≡MM-X*-PId(2s) (In the formulas, the inactivated PId is shown as the final product on the right side, and the identity (≡) on the right side simply introduces shorter and longer notations for the same activation-mobility macromer where the activating terminal group is explicitly shown (MM-X*) or only implied (MM*).) 【0028】 Figure 4 also shows that the activation of MM104 to MM-X*104* in step (2) prepares the molecule for polymerization with a second MM104 in the subsequent step (3): [ka] This results in two MM104s joined together in the final state: [ka] 【0029】 This polymerization, or bonding step (3), transfers the highly reactive electronic state from the first activated MM-X*104* to the second MM104. Thus, polymerization step (3) deactivates the activated radical X* / terminal group 103* of the first MM-X* to the deactivated terminal group (Xd) 103d, while activating the second MM to MM-X*, which has its own radical center. This transfer in step (3) in Figure 4 can be represented by the following symbols: MM - X* + MM = MM - MM - X* (3s) 【0030】 More specifically, activatable terminal groups are denoted by Xa or 103a, and inactivating terminal groups are denoted by Xd or 103d. Thus, polymerization step (3) can be written in more detail as follows: MM-X*+MM-Xa=MM-Xd-X*-MM. (3s') The inventors use these two notations interchangeably. In the reaction in step (2) when the activating photoinitiator PI*106* activates the activatable terminal group Xa103a at the end of the immobile macromer IM105 to IM-X*, polymerization step (3) takes the following form: MM-Xa+IM-X*=IM-Xd-X*-MM. (3s'') 【0031】 In the detailed step (3) above, MM104 having two activatable terminal groups 103 is shown, both of which are activated by PI*106*, and therefore have activated radicals at both of its ends: X*-MM-X*. Such MM104 is sometimes called bifunctional for this reason. In the MM-MM bonding / polymerization reaction of step (3), only one of these radicals was involved. This reaction allows the bifunctional MM to still enter a second polymerization reaction via the other radical X*103*. Such bifunctional MM104, which can polymerize at both terminal groups, can rapidly grow a highly branched polymer network, as described below. 【0032】 Figures 5A-C show that this three-step photo-induced binding / polymerization of the two MM104s tends to immobilize them. The immobilization of the mobile macromer MM104 is, naturally, the driving force behind the change in photopower, as shown in Figure 1. Figure 5A shows the first mechanism of this immobilization. It is recalled that LAL100 has two types of macromers: a mobile macromer MM104 that is free and moves within the network 101, and an immobilized macromer IM105 that is already linked to the crosslinker XLK102 of the silicone network 101 during molding / curing and is therefore immobilized. Figure 5A shows the photo-induced binding of the mobile MM104 to the already immobilized IM105, induced by activated PI*106. Returning to Figure 4, in step (2), activated PI*106* can activate the activatable end group 103a of IM105, converting it to IM*105*. In the subsequent polymerization step (3), nearby MM104 can bind to activated IM*105*. In this step (3), the immobile macromer IM105 is inactivated to inactivated IM105d, and its radical center is moved onto MM104 to convert it to activated MM*104*. In the sister reaction, in step (2), activated PI*106* can activate MM104 to MM*104*, and in the subsequent step (3), MM*104* can bind to IM105, thereby inactivating MM104 and activating IM105 to IM*105*. In both processes, MM104 binds to IM105, and their complex has an activated terminal group 103*. Binding to the immobile macromer IM105 naturally also immobilizes the mobile macromer MM104. This process is often called "grafting" because MM104 grafts onto the Si polymer network 101. Grafting is induced by UV irradiation, which activates PI106 to PI*106*, and then grafts MM104 onto the Si polymer network. Therefore, this UV-induced grafting is the main driving force behind relatively rapid zone formation. 【0033】 Figure 5B shows the second mechanism of immobilization: photo-induced binding of mobile MM104 to another mobile MM-X*104* activated by PI*106*. Figure 4 shows that as a result of this process, the first activated MM-X*104* is deactivated to MM-Xd 104d, while the second activatable MM-Xa 104a becomes newly activated MM-X*104. This binding / polymerization step (3) can be repeated many times without further activation by photoactivating PI*106*. This is the self-sustaining polymerization process described earlier, which continues to repeat itself without repeated absorption of UV photons. This process is sometimes called chain polymerization. Chain polymerization can continue spontaneously in a spontaneous, self-sustaining manner without UV light, because it can repeat itself beyond the original PI106 that initially nucleated this MM104 cluster without activating any additional photoinitiator PI106. The rate is lower than that of the initial PI*-induced step (2), because the reactivity, or reaction rate, of the UV-activated PI*-induced step (2) is significantly faster than the reactivity of chain polymerization. 【0034】 Figure 5B shows that a single initial photo-induced activation of PI106 can nucleate the development of a network in which the number of MM104 increases along the zigzag backbone. Figure 5C shows, with reference to equation (3), that in an embodiment where MM104 is bifunctional, side branches can be nucleated by a second photoactivated PI*106*, and further side branches can be nucleated by further photoactivated PI*106*. The resulting complex clusters or networks of MM104 rapidly increase in size and can develop many complex branches. As the cluster size grows, the probability of entanglement with the silicone network 101 increases, and therefore the mobility of these clusters rapidly decreases. This entanglement of the growing MM104 clusters with the silicone matrix 101 occurs via mechanical constraint and frustration rather than by the formation of chemical bonds. Nevertheless, this also effectively immobilizes the MM104. Thus, this process in Figures 5B-C can be characterized as a chain polymerization resulting in entanglement. 【0035】 The grafting and entanglement processes in equations (2) and (3) and Figures 5A and C ultimately deactivate the mobility of MM104, rendering them virtually immobile IM105. This immobilization induces a change in the shape of LAL100, as described in relation to Figure 1. Rapid UV-induced grafting and the initiation of entanglement by UV-induced chain polymerization are both mechanisms for rapid zone formation. Even in the absence (or minimal presence) of UV irradiation, subsequent slow but self-sustaining entanglement by chain polymerization is the primary mechanism for slow power fluctuations. These power fluctuations may be amplified by the low-intensity UV component of ambient light. 【0036】 This paper describes methods, techniques, and chemical designs for controlling and reducing these unintended polymerization processes that drive grafting and entanglement, primarily to reduce undesirable, long-term, slow light power fluctuations, but in some cases to reduce even shorter-term zone formation. First, we consider processes for terminating these undesirable polymerization mechanisms. Next, we describe embodiments that utilize and control these termination processes to suppress and minimize power fluctuations in LAL100. The first process for terminating chain polymerization occurs when two radicals X*103* at the end of each MM104 or IM105 enter physical proximity to each other, inactivating each other and thus terminating their growth, as indicated by the following symbols: X* + X* = XX(4s) 【0037】 More detailed notation: MM - X* + MM - X* = MM - XX - MM. (4s') Several other processes that limit or influence the rate of unintended polymerization are related to the oxygen inevitably present in the aqueous environment of the embedded LAL100. The O2 concentration in the aqueous humor of the eye is approximately 0.5 ppm, substantially lower than the 6 ppm typical of water exposed to atmospheric conditions. The O2 concentration inside LAL100 (abbreviated as [O2]) equilibrates with the O2 in its surrounding aqueous environment. Notably, since the oxygen solubility in LAL100 is approximately 8 times greater than in water, the [O2] inside LAL100 equilibrates with the 0.5 ppm of aqueous humor, which is approximately 8 times higher, at about 4 ppm, as will be further discussed below. This oxygen concentration [O2] is maintained by the homeostasis of the human body: when the oxygen inside LAL100 begins to be consumed by chemical reactions, the surrounding aqueous humor tends to restore this concentration somewhat quickly. As will be discussed below, even at such low concentrations, oxygen plays an important role in the chemistry of LAL100. Therefore, power fluctuations can be suppressed by controlling the oxygen content of LAL100. 【0038】 In a particularly relevant example, the activating photoinitiator PI*106* can react with oxygen instead of activating the mobile macromer MM104. This reaction produces a less active PI derivative, PI-OO, indicated by the following symbols: PI* + O2 = PI - OO(5s) An example of a response (5s) using this symbol is explicitly shown as follows: [ka] 【0039】 In the formula, following convention, the remaining parts of the PI molecule are denoted by R' and R''. Another example is the benzoin PI106 mentioned above, where the reaction of the activated PI*106* radical with oxygen ultimately produces benzoic acid: [ka] 【0040】 The reactivity of these low-activity PI derivatives, such as oxidized PI-OO, is much lower than that of activated PI*106*, which is why PI-OO is not labeled with an asterisk (*). Visibly, the activated photoinitiator PI*106*, which reacts with oxygen, depletes the concentration of PI*106*, thus beneficially reducing unintended polymerization. For completeness, it should be noted that low-activity PI-OO can still induce the PI-OO + MM = IM-X* reaction, but the reaction rate is much slower than that of the reaction involving PI*106*. In informal terms, low-activity PI derivatives PI-OO (and its variants such as PI-OH) are referred to as "zombie photoinitiators." 【0041】 For process (5), the presence of oxygen is detrimental to the regulating process because it reduces the concentration of the photoinitiator intended to induce the regulation of LAL. However, the presence of oxygen is very useful for stabilizing LAL100, especially against long-term power fluctuations after lock-in, because it inactivates potential causes of unintended polymerization, including power fluctuations. Notably, the reaction rate of the PI* + MM = IM - X* reaction in process (2) is k1 = 10 2 ~10 4 While the reaction rate is L / mol* seconds, the reaction rate of the PI* + O2 = PI - OO reaction in process (5) is k2 = 10 6 ~10 8 The reaction rate is approximately L / mol* seconds. The ratio of these two reaction rates is k1 / k2 = 10 -2 ~10-4 In some embodiments, the range is 10 -3 It is estimated that these rates are on the order of . These rates, of course, depend on various factors such as temperature and concentration. Therefore, as long as oxygen is present in LAL100, the majority of radicals PI*106* react with oxygen rather than the mobile macromer MM104. Thus, thoughtfully including oxygen in LAL100 at a suitable concentration is an efficient way to control polymerization, as it significantly reduces or halts unintended photopolymerization that leads to zone formation or power fluctuations. It is explained below that simply increasing [O2] during preparation is not expected to yield benefits, as it is expected that [O2] will return to equilibrium with the corresponding [O2] in aqueous humor. Therefore, embodiments emphasize physicochemical design for increasing the oxygen content of LAL100. An example is modifying the aforementioned oxygen solubility in LAL100. 【0042】 Figures 6A and 6B show that one of the results of the above process is that there is an initial period in which UV radiation has already entered LAL100, but there is little to no power change, even though the adjustment or lock-in process, or unintended zone formation, has begun. This is because most of the photoinitiator molecule PI106, even if activated by UV photons, is subsequently consumed entirely by the oxygen present in LAL100 through the fast and dominant step (5): PI* + O2 = PI-OO process. Figure 6A shows the time evolution of the spatial profile of the radius-dependent oxygen concentration [O2](r) during this initial period as oxygen is consumed and depleted when LAL100 is exposed to UV irradiation. As long as there is a finite oxygen concentration [O2](r) in the irradiated region, the polymerization rate of MM104 remains minimal. Polymerization and the associated power change begin when oxygen is completely consumed and depleted by process (5) at t (activate), as shown by the outermost [O2](r) concentration profile. Figure 6B qualitatively illustrates that this dynamic delays the power change ΔP(t) of LAL100. Figure 6B shows that the slope of the power change curve ΔP(t) is initially low during the phototuning procedure because photo-induced polymerization is suppressed even as oxygen is consumed by process (5). Once substantially all of the oxygen has been consumed by time t(activate), photopolymerization is no longer suppressed by oxygen, and the slope of the power change curve ΔP(t) increases substantially. In embodiments, the chemical composition, concentration, and reaction rate of the silicone network 101, mobile macromer MM104, switchable and non-switchable ultraviolet absorbers, and photoinitiator PI106 are such that this slope of the time-dependent power tuning curve can more than double after time t(activate), when oxygen has been almost completely consumed in the irradiated area during the phototuning procedure. In this specification, t(activate) may range from 3 to 100 seconds in some embodiments and from 5 to 50 seconds in other embodiments. If the slope of the ΔP(t) curve changes significantly, the slope averaged over a period of 5 to 10 seconds after t(activate) may be at least twice as large as the slope averaged over a period of 0 to t(activate).In some cases, this slope ratio may be greater than 1.5. Referring back to FIG. 6A, in some embodiments, the oxygen concentration [O2] at the center of the LAL 100 decreases by more than 50% during the t(activate) time. In some other LALs 100, the oxygen concentration [O2] at the center of the LAL 100 decreases by more than 90% during the t(activate) time. 【0043】 From a kinetic perspective, the above-described reaction involving PI can be represented by the following rate equation: d[PI*] / dt = +αI(UV)[PI] - k1[MM][PI*] - k2[O2][PI*] (6) 【0044】 Here, I(UV) represents the intensity of the incoming UV irradiation, α is the efficiency constant, [PI*], [PI], and [MM] represent the concentrations of the compounds PI*, PI, and MM, and k1 and k2 are the reaction rates of the processes (2) and (5) introduced above. As described above, in a characteristic embodiment, k1 << k2, while [O2] is about 4 ppm, [MM] = 10 - 50% by mass, and in some embodiments, 20 - 30% by mass. The ratio of the total rates (including concentrations) of the two processes that consume PI* is given by R = k2[O2] / k1[MM]. This can also be considered as the ratio of the PI quenching rate Rq = kq[X*][O2] to the additional rate Ra = ka*[X*][MM], from which R = Rq / Ra = kq[O2]) / ka[MM], and kq = k2 and ka = k1 are identified as before. 【0045】 The embodiments can reduce undesirable power fluctuations by having a high R ratio, where a high R ratio indicates that most activated PI*106* are quenched by oxygen instead of activating MM104 into radical MM-X*104*. In some embodiments, R may be in the range of 1 to 1,000, in some embodiments in the range of 1 to 100, and in other embodiments in the range of 1 to 10. In such LAL100s where R>>1, most of the PI* radicals 106* are neutralized / consumed by oxygen, thereby reducing undesirable polymerization of the mobile macromer MM104. In contrast, in LAL100s where R is close to or less than 1, most of the PI* radicals 106* actively promote polymerization of the mobile macromer MM104, thereby inducing uncontrolled polymerization and power fluctuations. Therefore, creating LAL100s with an R ratio much greater than 1 is another efficient method for polymerization control and preventing power fluctuations. 【0046】 Another important oxygen-related reaction that can reduce chain polymerization is when the chain polymerization-driving radical X* reacts with oxygen instead of other mobile macromers MM104. This reaction converts the highly reactive radical X* into a less reactive XOO* compound, symbolized as follows: X* + O2 = XOO*. (7s) Or, in more detailed notation: MM - X* + O2 = MM - XOO*. (7S') Low-activity radicals XOO* are often peroxy (or peroxyl) radicals. Because XOO* compounds are far less reactive than radical X*, this process significantly inactivates radical X*. While the ability of such low-activity XOO* compounds to initiate subsequent chain polymerization is suppressed, it is still not zero, as will be discussed later. 【0047】 With these preparations (5) to (7), the rate equation for oxygen concentration can be written as follows: d[O2] / dt=β([Oeq]-[O2])-k2[O2][PI*]-k3[O2][X*]. (8) This process evolves spatially by diffusion. Thus, explicitly representing the spatial dependence, it is as follows: ∂[O2] / ∂t = D∂ 2 [O2] / ∂r 2 -k2[O2][PI*] - k3[O2][X*](9) This equation needs to be solved, among other things, using appropriate boundary conditions that fix [O2] to [Oeq] at the boundary of LAL100, where [Oeq] is the equilibrium oxygen concentration of LAL100 equilibrated with the aqueous humor of the eye. β is a constant representing the rate of the oxygen equilibration process, and k3 is the reaction rate of process (7). There are rate equations corresponding to the concentrations of [X*], [MM], and the immobilized macromer [IM], but these will not be described in detail. 【0048】 Next, we describe the dynamics of [O2] derived from equations (5) to (9), which are linked to similar equations for [X*] and [MM] before, during, and after the adjustment or lock-in procedure. Figure 7 shows the concentration of the activated photoinitiator radical PI*106* [PI*] and the concentration of oxygen [O2] in LAL100. The adjustment or lock-in procedure is started at t(start) by applying a UV irradiation beam and ended at t(end) by switching the UV beam off. Before the UV beam is applied, oxygen is present at a concentration [Oeq] in equilibrium with the aqueous humor of the eye. Also, in the absence of the incident UV beam, no activated PI* radicals are present before t(start), and therefore [PI*] is negligibly small. When the UV beam is applied at t(start), the PI*106* radical is generated by UV photons via process (1), or step (1). The fastest process involving the activated PI* radical 106* is process (5), which is the consumption of PI* by oxygen. Therefore, most UV-activated PI*106* is rapidly consumed by process (5). Thus, after the UV beam is switched on at t(start), [O2] rapidly decreases from [Oeq], while the [PI-OO] concentration (not shown) increases accordingly, and the negligible [PI*] remains at a minimum as shown. In this process, the decrease in [O2] suppresses the ratio R from its high initial value. As a result, the PI* radical 106* is consumed less and less by reacting with oxygen and more and more by polymerizing the mobile macromer MM104. 【0049】 When the oxygen concentration [O2] reaches nearly zero at t(activate), the PI* radical 106* is no longer rapidly consumed by oxygen, and from t(activate), as shown in the figure, [PI*] begins to increase rapidly due to UV irradiation. After t(activate), the PI*106* radical mainly induces polymerization and immobilization of the mobile macromer MM104, thereby inducing the regulation of the LAL100's light power. [PI*] flattens at a dynamic equilibrium value determined by the balance between the generation of PI*106* by the UV beam and the consumption of PI*106* by the polymerization of MM104. In formal terms, this is achieved by setting the right-hand side of equation (6) to 0. 【0050】 Finally, when the UV beam is switched off at t(end), the PI*106* radical concentration [PI*] begins to decrease according to equation (6), and the oxygen concentration [O2] rises again to its equilibrium value [Oeq] according to equations (8)-(9). The typical duration |t(end)-t(start)| of such a control or lock-in procedure is 20-200 seconds, and in some embodiments, 30-100 seconds. The graph in Figure 7 examines the central role of oxygen in influencing the PI*106* concentration [PI*] at every stage of the UV irradiation process. This examination provides a useful context for analyzing and controlling power fluctuations induced by the reactions of MM104, PI*106*, and oxygen, mainly over long periods after t(end). 【0051】 Figure 7 illustrates the photomodulation process by nominally and intentionally applying a UV beam, but is useful for unintentional UV-induced zone formation processes and the UV-induced portion of power fluctuation processes. Zone formation involves UV irradiation at a lower intensity than used in the modulation or lock-in procedure, such as when a patient is inadvertently exposed to sunlight without wearing the required sunglasses before lock-in. If the inadvertent exposure continues for a sufficiently long time, the O concentration [O2] may decrease to a level low enough to induce polymerization of MM104 and alter the shape of the LAL100 in the irradiated zone, accelerating the formation of PI* (as occurs after t(activate) in Figures 6-7). As previously mentioned, LAL100 with a front protective layer 110 minimizes and typically eliminates the possibility of such zone formation. 【0052】 Figure 8 shows that under weak ambient UV irradiation, UV activation processes (1) and (5) reach a kinetic equilibrium with a very small but non-zero PI* radical concentration [PI*]. This [PI*] concentration is very small because the UV light is insufficient to reduce [O2] to zero, so most of the activated PI*106* reacts with oxygen and transforms into the zombie photoinitiator PI-OO. Nevertheless, this very low but non-zero [PI*] can induce undesirable polymerization and thus induce a power fluctuation ΔP(t) that increases over several hundred hours, as shown. From this description, it is clear that LAL100 with a chemical composition that accommodates more oxygen will have a lower equilibrium [PI*] and therefore a slower UV-induced power fluctuation. 【0053】 The above description was directed towards the UV-induced component of power fluctuations. Typically, the majority of power fluctuations are caused by chain polymerization, which may be initiated by UV absorption but can also continue spontaneously and self-sustainingly even without UV irradiation. Having described the role of oxygen in controlling and managing UV-induced polymerization, we will now move on to describing its role in controlling chain polymerization. Oxygen also limits and suppresses this polymerization process by process (7) which converts radicals, i.e., the active terminal group X*103*, into much less reactive XOO* groups such as peroxy. Therefore, an efficient control design to suppress unintended polymerization in LAL100 is to incorporate oxygen into LAL100 that reacts with the X* radical 103* (of the activated mobile macromer MM-X*104*) via process (7) and converts them into weakly active radicals XOO* or MM-XOO*. However, since the reactivity of these low-activity radicals XOO* is still not zero, they may still drive slower power fluctuations over hundreds of hours. Therefore, Figures 9A-B show that some embodiments of LAL100 control and reduce this unintended polymerization by including the radical scavenger RS125 to further deactivate these oxidized low-activity radicals XOO*, represented by the following symbols: RS + XOO* = XOOd(10s) 【0054】 Here, XOOd represents an inactivated XOO* group reacted with the radical scavenger RS125. In more detailed notation: RS+MM-XOO*=MM-XOOd(10s') A promising example of such a radical scavenger RS125 is given by formula: [ka] This is tocopherol, or vitamin E, as shown by [the symbol]. 【0055】 The radical scavenger RS125 can be tocopherol in its different α, β, γ, and δ forms. The O* of XOO* reacts with the OH of the tocopherol terminal group, and this electron exchange neutralizes the O* radical center, thereby converting XOO* into an inert group. Other radical scavengers include ascorbic acid, butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), or 2,6-di-tert-butyl-4-methoxyphenol. In general, many types of radical scavengers are known. A common property of many of them is that they are proton donors that have a preference for reacting with peroxy radicals. 【0056】 The photoactivation polymerization steps (1) to (3) and polymerization control design processes (4) to (10) described above are comprehensively summarized in Figures 10A to B. The numbers in the circles indicate the labels for the steps or processes. The frames around the chemical formulas (e.g., PI-OO and MM-Xd-XOOd-MM) indicate that the polymerization control design is made to inactivate these compounds so that they do not participate in further polymerization. The pentagons around O2 and the radical scavenger RS125 indicate that these are important agents for the polymerization control design. Figures 10A to B show both immobilization by entanglement via the chain polymerization process and immobilization via the grafting reaction pathway. Figure 10A uses detailed chemical notation that explicitly shows the terminal group X103 of MM104 and IM105 in three states: Xa of activatable X, X* of activated X, and Xd of inactivatable X, while Figure 10B uses the most compact notation, where MMa represents a mobile macromer with the activatable terminal group Xa103a, MM* represents a mobile macromer with the activatable terminal group X*103*, and MMd represents a mobile macromer with the inactivatable terminal group Xd103d. These two notations are provided as alternative analogous descriptions of the same chemical pathway. 【0057】 Returning to the polymerization control process (10), some LAL100s utilize a control design that introduces the radical scavenger RS125 to the LAL100s, which reacts with low-activity radicals XOO* and further deactivates them to the nearly inactive group XOOd via process (10). Advantageously, the reaction rate k(RS-XOO*) of tocopherol with low-activity XOO* / peroxy radicals is fast, while its reaction rate k(RS-PI*) with activated PI*106* is slow. Thus, tocopherol does not substantially slow down the regulation and lock-in process dependent on the PI*106* radical, but rather quite efficiently completes the suppression of unintended chain polymerization via process (10), which was already substantially suppressed by oxygen via process (7). In particular, Figure 9A shows how the radical scavenger RS125 inactivates the still moderately active radical center of the low-activity radical XOO*, and Figure 9B shows that, after the lock-in is complete, polymerization and the corresponding power shift ΔP(t) are suppressed as long as both oxygen and RS125 tocopherol are present until all RS125 tocopherol is consumed. 【0058】 Under normal circumstances, the UV component of ambient light experienced by the patient from sunlight or indoor lighting reduces the PI concentration [PI] of LAL100 to zero over a period of time, for example, in the range of 100 to 1,000 hours, by activating PI106 to PI*106*, which is then consumed by oxygen or the polymerization process. In some typical examples, this time may be in the range of 300 to 500 hours. This time may be referred to as the fluctuating activity time. During this fluctuating activity time, essentially all PI106 is consumed by the UV component of ambient light. Therefore, polymerization control designs and processes to protect against PI-driven power fluctuations need to be effective only over this fluctuating activity time of several hundred hours, not over the decades of LAL100's lifespan. Accordingly, polymerization control designs and processes that can effectively suppress the main mechanism of LAL100 power fluctuations include the following: (1) Prepare LAL100 containing enough oxygen to reduce the activity of the mobile macromer 104 and immobilizing macromer 105 by inactivating the photoinitiator PI106 and converting the radical X*103* of the mobile macromer 104 and immobilizing macromer 105 into a low-activity radical XOO*. Since the [O2] in LAL100 is in equilibrium with aqueous humor, an indirect method is required. (2) Prepare LAL100 containing enough radical scavenger RS125 to broadly inactivate the low-activity radical XOO* over a variable activity time. Details of the polymerization control designs and processes for these classes are described further below. 【0059】 Figures 11A-B illustrate in some detail the effect of the radical scavenger RS125 on the power fluctuation dynamics of Figure 8. Figure 11A shows that in the absence of the radical scavenger RS125, when LAL100 is exposed to low-intensity / ambient UV radiation, UV photons begin to activate the PI*106* radical by process (1) / step (1). The PI*106* generation process is limited by process (5), in which oxygen transforms the PI*106* radical into a much less reactive PI-OO zombie photoinitiator. These competing processes (1) and (5), as shown, set a kinetically balanced [PI*] that depends on [O2]. Process (5) also consumes oxygen and therefore tends to decrease [O2], while equilibration to [Oeq] by aqueous humor via process (8) tends to increase [O2]. These two competing processes, as shown, set a kinetically balanced [O2] concentration. Then, as [O2] converges to a steady value, the concentration [PI*] also converges to a steady value, as shown. These steady concentrations of [O2] and [PI*] remain until all PI106 is consumed, at which point [PI*] returns to its initial value close to zero, and [O2] also returns to its initial value in equilibrium with aqueous humor. These photoactivated PI*106* induce slow power fluctuations in LAL100, as shown in Figure 8, but the PI-OO zombie photoinitiators generated by oxygen have minimal residual reactivity and therefore do not increase power fluctuations. 【0060】 Figures 11A-B, in relation to the above, show that oxygen converts some of the active terminal groups X*103* into less active XOO* radicals by process (7). The resulting XOO* radicals induce further polymerization and are therefore the further driving force of the power shift ΔP(t). Figure 11A shows that the concentration of these XOO* radicals increases over time as long as PI*106* radicals are generated by ambient UV irradiation. XOO* radicals may be additionally generated by UV-induced PI* radical 106*-free chain polymerization followed by an oxygen-driven process (7). This process can continue even after lock-in because lock-in causes MM104 to polymerize predominantly in the central region, and therefore MM104 that did not reach the periphery of LAL100 with sufficient intensity from the lock-in beam may remain, which can then flow very slowly into the central region of LAL100, allowing chain polymerization and XOO* generation to continue. Thus, over several hundred hours, the low-activity radical concentration [XOO*] may still increase by a small percentage of steps, possibly even after lock-in, as shown in Figure 11A, which can induce slow power fluctuations in LAL100. 【0061】 Figure 11B shows that several polymerization control methods can even suppress this residual power fluctuation by utilizing process (10), in which the radical scavenger RS125 inactivates low-reactive XOO* groups. As shown, process (10) suppresses the generation of XOO* groups until all RS125 is consumed and [RS] becomes zero. When the amount of RS125 added increases with the polymerization control design, the increase in [XOO*] concentration lags behind, and its kinetic equilibrium value, or plateau value in an approximate sense, decreases. In some cases, even the rate of increase (its slope) of [XOO*] decreases with the introduction of RS125. Naturally, the decrease and control of [XOO*] concentration also occurs because the radical scavenger RS125 is consumed over time, so its concentration [RS] decreases over time as shown. Next, we consider various processes involving UV absorbers. Figures 2A and 2B show that recent improvements to LAL100 have introduced an additional front protective layer 110. Figure 2A is a top view of LAL100. Figure 2B is a side view of LAL100, which shows the front protective layer 110 and an optional, often useful, rear protective layer 120. The front protective layer 110 typically includes a switchable UV absorber that can be switched between a strong UV absorption configuration and a weak UV absorption configuration. 【0062】 One embodiment of a switchable UV absorber is azobenzene, known to change its absorption properties upon light stimulation. Azobenzene is one of the simplest examples of the family called azo compounds, by the general formula RN=N-R', where R and R' may be aryl, alkyl, or from the group thereof. Azobenzene is known to have two conformations with different bond angles between the N=N double bond and one of the two phenyl rings. The "trans" conformation has high absorption in the UV spectrum, with a peak in the wavelength range of 360-370 nm, and the absorption involves a π-to-π* electron transition. Similar absorption peaks are also present in various functionalized azobenzenes. UV light with a wavelength around 365 nm acts as a high-to-low modulation stimulus 310-htl, which can convert azobenzene from its high-absorbing isomer 300-h with the transconformation to its low-absorbing isomer 300-l with the cisconformation. As shown, the cis-conformation exhibits much lower absorption around the 365 nm wavelength. Therefore, azobenzene is one embodiment of a switchable UV absorber for the front protective layer 110, which in the trans-conformation nearly blocks incoming UV rays but can switch to the low-absorption cis-conformation to allow regulated radiation to pass through to LAL100. For completeness, it should be noted that azobenzene-based compounds may have further conformations. 【0063】 Besides azobenzene, many other embodiments of switchable UV absorbers exist. A switchable UV absorber may be an azo aromatic compound, diazene, azopyrazole, dienylethene, fulgicide, azulene, spiropyran, ethene aromatic compound, a macromer of one of these compounds, a polymer of one of these compounds, a composition containing one of these compounds, a composition containing one of these compounds as a side chain, a composition containing one of these compounds as a main chain with a side chain, a nanoparticle-like substance bound to one of these compounds, or one of these compounds dissolved in an ionic fluid. A switchable UV absorber may also be a polymer in which any of the compounds listed above are incorporated into the polymer host polymer network itself, and therefore do not need to be incorporated as a side chain. Some such compounds may include polymers that bend in response to light. This specification continues by outlining a broad list of embodiments of switchable UV absorbers. 【0064】 As mentioned above, the azo aromatic compound may be, for example, an azobenzene that exhibits the following conformational changes: [ka] 【0065】 In other embodiments of the switchable UV absorber, the azo aromatic compound may be 4-methoxyazobenzene: [ka] 【0066】 The switchable UV absorber may also be indazole, allylated azobenzene with various spacer linkages, or another version of phenylazopyrazole as shown: [ka] 【0067】 In yet another embodiment, the azo-pyrazole may be vinylphenylazopyrazole (VPAP): [ka] 【0068】 Finally, in some embodiments, the ethene aromatic compound may be stilbene: [ka] 【0069】 Embodiments of such switchable absorbers are described in great detail in the commonly owned U.S. Patent Application 16 / 658,142, title: "Light Adjustable Intraocular Lens with a Modulable Absorption Front Protection Layer," by Goldshleger et al., the entirety of which is incorporated herein by reference. Under ambient light illumination, these switchable absorbers absorb UV light very efficiently. However, upon irradiation with high doses of UV light, the internal dynamical balance between the two (trans and cis) conformations of the VPAP molecule shifts, causing the front protection layer 110 to become partially transparent to UV. This change opens the door for the regulated UV beam to enter the bulk of the lens and initiate the regulated effect described above. Once the regulated irradiation is complete and the UV beam is switched off, the front protection layer 110 switches back to strong UV absorption. This absorption switching mechanism protects the VPAP front protection layer 110 from unintended regulation by some of the still-active mobile macromers from implantation to lock-in. 【0070】 Switching between a strong UV-absorbing configuration and a weak UV-absorbing configuration can degrade the structure of the UV absorber in a small proportion of these switching events. Furthermore, these reciprocal switching events proceed as the system maintains its steady state. Therefore, a switching UV absorber may be assigned a half-life τ(sUV) that represents how many switching events it takes for 50% of the structure of the switchable UV absorber to degrade and lose its switching ability. This half-life τ(sUV) is based on the number of switching events the switchable UV absorber can survive multiplied by the characteristic time between switching. This switching time depends on temperature and chemical parameters. LAL100 having a switchable UV absorber whose structure degrades more quickly will lose UV protection from the front protective layer 110 more quickly. Since lock-in typically occurs 15-30 days after implantation, and UV exposure typically has an impact of less than 10 hours per day, embodiments of switchable UV absorbers having a half-life τ(sUV) of more than 200 hours in the implanted environment may be advantageous. Some embodiments of the switchable UV absorber may have a half-life τ(sUV) exceeding 400 hours in an embedded environment. 【0071】 The same degradation process can also be observed in terms of the number of switching events. Depending on its specific chemical composition, the switching UV absorber molecule begins to show an increasing degree of degradation after a number of switching events that can range from 50,000 to 500,000, and in some cases from 100,000 to 200,000. Because activated PI*106* or XOO* molecules migrate to the front protective layer 110, the switching UV absorber may also degrade. Furthermore, after PI106 is consumed in the front central region, PI106 can migrate from the periphery of the lens or any other region to this front central region. 【0072】 Next, several polymerization control designs are described that control and suppress undesirable and uncontrolled polymerization, and thus reduce undesirable power fluctuations of LAL100. Embodiments of LAL100 can combine more than one of the listed polymerization control designs to amplify the benefits and advantages. (1) One of the broad polymerization control design principles is to produce LAL100 that can accommodate the highest possible oxygen concentration. Some LAL100s may be able to accommodate oxygen concentrations in the range of 0.5–50 ppm. Other LAL100s may be able to accommodate oxygen concentrations in the range of 0.5–20 ppm, 4–20 ppm, or 6–20 ppm. The initial oxygen concentration of LAL100 is expected to equilibrium with the 0.5 ppm oxygen concentration of the aqueous humor of the eye after implantation. Therefore, LAL100s need to have chemical and physical properties that allow them to maintain higher oxygen concentrations even after equilibrium with the aqueous humor. One design principle is that, as previously established, LAL100s with a higher R=k2[O2] / k1[MM] ratio can retain excess oxygen and thus more efficiently suppress undesirable power fluctuations. In the above equivalence notation, R can also be expressed as the product of the oxygen concentration [O2] multiplied by the oxygen-driven photoinitiator quenching rate kq (indicated as k1 above), with respect to the mobile macromer concentration [MM] multiplied by the photoinitiator-driven polymerization addition rate ka (indicated as k2 above): R = kq[O2] / ka[MM]. 【0073】 In some embodiments, R may be greater than 10, 100, or 1,000. In a silicone compound of LAL100 in equilibrium with aqueous humor having an oxygen partial pressure, the oxygen concentration is given by the product of pressure and oxygen solubility. Solubility, in turn, is given by dividing the oxygen permeability coefficient by the diffusion coefficient. Since it is not possible to comfortably modify the oxygen concentration of the aqueous humor of the eye, polymerization control designs are directed towards favorably adjusting the solubility or diffusion coefficient of LAL. In typical silicones, the oxygen permeability coefficient by diffusion is 500-800 "barrels" in non-SI units. In SI units, the permeability coefficient is given in units of mol / (m * seconds * Pa), where 1 barrel = 3.35 * 10⁻¹⁵ -16The coefficient of oxygen permeability is mol / (m*seconds*Pa). In existing embodiments of LAL100, the oxygen permeability coefficient is less than 100-200 bars. Therefore, the chemical design of LAL100 can be improved by increasing the oxygen permeability coefficient, and thus the solubility, while decreasing the oxygen diffusion coefficient, perhaps towards the level exhibited by ordinary silicones. LAL100 with such a chemical design will have an improved oxygen concentration [O2] and thus reduced power fluctuations. Therefore, some LAL100s may have a chemical composition that allows for oxygen concentrations in the range of 4-20 ppm, and in some cases 6-20 ppm, by means of oxygen permeability, solubility, and diffusion coefficient. 【0074】 Another way to capture these polymerization designs is to use equilibrium equations: [O2] (LAL) =( S LAL / S aq )[O2] aq (11) In the formula, [O2] LAL and [O2] aq This is the oxygen concentration in LAL and aqueous humor, and S LAL and S aq This is the solubility in LAL and aqueous solution. In some characteristic silicones such as PDMS, the specific S is LAL / S aq It is approximately 8. Therefore, the amount of [O2] in aqueous humor aq Even if it is only about 0.5 ppm, in LAL there is about 4 ppm of [O2] LAL It is possible to reach this [O2] by having at least one of the polymer silicone network 101 and the mobile macromer MM104 contain fluorine and at least one of the fluorine-containing functional groups. LAL This further increases the ratio S. Therefore, in some LAL100s, the ratio S LAL / S aq It may be greater than 5, and in some embodiments, it may be greater than 10. 【0075】 (2) In some LAL100s, the R ratio can be increased not only by increasing the oxygen concentration [O2] but also by decreasing the reaction rate of the denominator k1 (or kq) that characterizes the polymerization process. The terminal group of the methacrylate of the mobile macromer MM is given by formula: [ka] It can be described by [this method]. 【0076】 In some LAL100s, the CH3 side group of the second carbon atom from the end may be replaced by a longer group or chain. In other LAL100s, one or both hydrogens may be replaced by CH3 or a longer side chain. More generally, the terminal group 103 of the mobile macromer MM104 may contain a side chain longer than CH3 methyl. Such MM104s have a slower polymerization addition rate k1 (or ka), and therefore a more favorable R ratio. (3) Some LAL100s may contain radical scavengers RS or antioxidants to suppress unwanted polymerization. In some LAL100s, the RS concentration [RS] may be in the range of 5 to 1,000 ppm, in some embodiments in the range of 10 to 500 ppm, and in yet other embodiments in the range of 50 to 200 ppm. The class of antioxidant radical scavengers is tocopherol or vitamin E. Notably, LAL100s with high [O2] and [RS] concentrations have been found to exhibit 50% lower power variability. Such a 50% reduction can be achieved, for example, in LAL100s with [O2] in the range of 5 to 10 ppm and tocopherol concentration in the range of 100 to 200 ppm. 【0077】 (4) Figure 12 shows that in some embodiments, power fluctuations can be suppressed by different polymer control designs. In some embodiments of LAL100, a mobile macromer MM can be injected into the underlying silicon polymer network, with only one of its ends being activated. In some embodiments, only one of the terminal groups of the mobile macromer MM104(1) is acrylate. Such macromers may be referred to as monofunctional macromers MM(1)104(1) to distinguish them from the difunctional macromers described above that form highly branched chain polymerization, as shown in Figure 5C. As shown in Figure 12, when the activating photoinitiator PI* activates such monofunctional mobile macromers MM(1)104(1), chain polymerization can then be initiated, but the chain-polymerized clusters have a linear backbone or a zigzag skeleton but no secondary or additional branching. Thus, chain polymerization after UV irradiation cessation is suppressed and limited, thereby reducing the probability and extent of unintended power fluctuations. It is worth noting that LAL100 having such a monofunctional mobile macromer MM(1)104(1) exhibits little to no unintended power fluctuations, although it may also limit modulated UV irradiation and induce less (intended) power changes. The power change achievable by UV irradiation is approximately 2.0-2.5D for LAL with bifunctional MM104, while it may be as little as 0.4-0.7D for LAL with monofunctional MM(1)104(1). 【0078】 (5) Further embodiments of LAL100 utilize polymerization control design to suppress undesirable power fluctuations by incorporating the sterically hindered macromer MM(sh)104(sh). The chemically activatable bond in the typical acrylate terminal group Xa103a of MM104(sh) is a double bond between the terminal carbon atom and the second-to-last carbon atom: [ka] 【0079】 The sterically hindered end group 103(sh) contains additional ligands around this C=C double bond to spatially hinder the approach of the radical center of the photoactivating photoinitiator PI*106*. For example, in the methacrylate end group 103, the H on the second C from the end is replaced with CH3. Other sterically hindered MM104(sh) may replace two hydrogens of the end C with other carbon atoms, each potentially forming a CH3 or a longer chain. Still other sterically hindered MM104(sh) may replace three hydrogens of the CH3 group on the second C from the end of the methacrylate end group 103 with carbon atoms, each potentially forming a CH3 or a longer chain. In other sterically hindered MM104(sh), the carbon atoms of the activatable double bond of the end group 103(sh) of the mobile macromer MM104(sh) also form bonds with CH3 methyl groups or longer chains. In other sterically hindered MM104(sh) groups, the carbon atom of the activatable double bond of the terminal group 103(sh) of the mobile macromer MM104(sh) also forms a bond with at least one other carbon atom. Furthermore, in other sterically hindered MM104(sh) groups, the terminal or second-to-last carbon atom of the activatable double bond of the acrylate terminal group 103(sh) of the mobile macromer MM104(sh) also forms a bond with a CH3 methyl group or a longer chain. 【0080】 Further options include using propyl, isopropyl, tert-butyl, sec-butyl, butyl acrylate, cyclohexyl, cyclopentyl, and phenyl acrylate to lengthen the chains connected to terminal group 103. Each of these sterically hindered structures tends to slow down the rate of the subsequent chain polymerization process, thereby reducing the rate of unwanted power fluctuations. [ka] 【0081】 (6) In some embodiments of LAL100, power fluctuations can be reduced by reoperating the underlying Si polymer network 101. It is conceivable that the mobile macromer MM preferentially binds to the polymer network 101 at its vertices generated by the crosslinking agent XLK102. Therefore, a polymer silicone network 101 with less crosslinking agent XLK102 results in fewer attachment vertices where the mobile macromer MM can bind to the underlying silicone network. Forming a silicone network 101 with less crosslinking agent 102 suppresses one of the two main processes that immobilize the macromers, as shown in Figure 5A. Thus, LAL100 with such reduced crosslinking agent density exhibits reduced power fluctuations. It is mentioned that less crosslinking tends to make LAL100 softer. Additionally, other polymer control designs reduce the incorporation of MM104 into the Si network 101 during the curing of LAL100. 【0082】 (7) In yet another embodiment, power fluctuations are reduced by a different design of the front protective layer 110. The front protective layer 110 has been described as including a switchable UV absorber or a UV blocker. However, as previously stated, some switchable UV blockers degrade over time, induced by in-system radicals such as PI*106* or XOO* radicals. The degradation of the switchable UV absorber over time allows an increasing rate of incident UV photons to pass through the front protective layer 110, acting as another driving force for unintended power fluctuations. 【0083】 To reduce this increasing amount of UV passing through the front protective layer 110, some embodiments of the front protective layer 110 may be formed in combination of switchable and non-switchable UV blockers. In such LAL 100, any potential degradation of the switchable UV blocker only leads to a partial loss of UV blocking, as the permanent UV blocker does not degrade and does not lose its ability to block UV light over time. In some LAL 100, the non-switchable UV absorber accounts for 5-50% of the total amount of switchable and non-switchable UV absorbers in the front protective layer 110. In some other embodiments, this percentage ranges from 10-40%, and in yet another embodiment, it ranges from 20-30%. 【0084】 When selecting non-switchable UV absorbers, several additional issues can be considered. One of these is that, because the absorption spectrum of VPAP has a tail extending into the visible spectrum beyond 400 nm, as shown in Figure 13, some switchable UV absorbers, such as VPAP, can change the visual experience to yellow rather than be comfortable for the patient. Therefore, the added non-switchable UV blockers may preferably be selected based on the characteristic of providing strong UV blockage for wavelengths below 400 nm, but minimal blockage for wavelengths above 400 nm, as shown in Figure 13. In other words, in some LAL100s, non-switchable UV absorbers efficiently absorb wavelengths shorter than 400 nm. Considerations regarding these wavelengths do not affect the control of the polymerization process and do not contribute to suppressing undesirable power fluctuations, and are therefore not an essential or necessary part of the polymerization control design. Rather, they are intended to improve the patient's overall visual experience. Examples include UV absorbers that efficiently absorb wavelengths shorter than 380 nm or 390 nm. A wide variety of suitable non-switchable UV absorbers or UV blockers are described in US6,851,804, "Readjustable optical elements," by JMJethmalani et al., and US9,119,710, "Adjustable optical elements with enhanced ultraviolet protection," both of which are incorporated herein by reference in their entirety. 【0085】 (8) As described above, in LAL100, the switchable UV absorber of the front protective layer 110 may degrade over time, either by partial diffusion from the bulk of LAL100 to the front protective layer 110, or by reaction with radicals, mainly PI*106* radicals or XOO* radicals, generated by UV radiation after unactivated PI106a has previously diffused into the front protective layer 110. To suppress this degradation mechanism, some LAL100s inhibit the diffusion of PI106 into the front protective layer 110. The hydrophobic PI photoinitiator 106 diffuses efficiently into the bulk hydrophobic silicon matrix 101 and the front protective layer 110. The water content of the hydrophobic bulk and front protective layer is typically 4% or less. In contrast, some LAL100s employ a polymerization control design by adding water to their front protective layer 110, thereby repelling the diffusion of hydrophobic PI106 into their front protective layer 110. Some LAL100s have a water content in their front protective layer ranging from 4% to 20%, while others have a water content ranging from 5% to 10%. Other control designs modify the hydrophobicity of the silicone polymer network 101 to alter the hydrophobicity of the front protective layer 110, and still others modify the hydrophobicity of the mobile macromer 104, thus suppressing internal diffusion of PI. Each of these polymer control designs reduces the degradation of the switchable UV absorber and therefore ultimately reduces undesirable power fluctuations in the LAL100. Some control designs can introduce an additional insulating layer between the bulk of the LAL110 and the front protective layer 110 to suppress internal migration of radicals PI*106* and XOO*. 【0086】 (9) In some embodiments of LAL100, the photoinitiator PI itself may be switchable between a protected state and an activatable state. In a sense, the protected state may be referred to as a “caged” state. In some embodiments, the UV-sensitive bond, which can be activated by incoming UV photons, may be protected by its molecular environment. For such a switchable PI to function, the protected state must first be switched or modified so that subsequent UV photons can decompose the UV-sensitive bond itself. The protected state may be switched by light of a first wavelength, different from the second wavelength UV light used for shaping irradiation to activate the photoinitiator PI106 and tune and lock in LAL100. For example, short-wavelength UV light can be used to change a protected state that is designed to absorb only such short-wavelength irradiation. Since such a switchable PI106 is “on demand,” it is inactive in the absence of activating UV light and therefore does not induce any undesirable polymerization and power fluctuations. In other words, the photoinitiator PI106 is less photoactivatable in the protected state than in the activatable state. In some embodiments, the photoinitiator is minimally photoactivatable under protected conditions. 【0087】 Such switchable PIs do not necessarily rely on multiphoton processes in the traditional sense. Multiphoton processes generally require high beam intensities that may exceed retinal safety levels due to their low efficiency. In these processes, a first photon often excites an electron to a first intermediate state, and then a second photon excites the same electron to a higher-energy target state. In the present invention, this excitation of the second electron constitutes the activation of PI106. In many multiphoton processes, the first intermediate state has a very short lifetime, so the second photon must be incident immediately after the first photon, often within picoseconds or nanoseconds. Such a short electron lifetime requires high intensity. In contrast, in embodiments of switchable PIs, the protective structure is a protective coupling or configuration that allows the switched state after absorption by the first photon to have a long lifetime. Thus, even if the second photon arrives considerably later, it can still activate the UV-sensitive coupling of PI106. Therefore, low-intensity beams can successfully operate these switchable PI control designs. 【0088】 (10) In yet another embodiment, the photoinitiator PI106 itself may be immobilized on the network 101. In such a system, the immobilized PI106 can still activate the MM104 mobile macromer. However, physically, these immobilized PI106 are mechanically and kinetically prevented from reaching the activatable end groups 103 of the mobile macromer MM104 and the immobilizing macromer IM105. In particular, molding irradiation activates the photoinitiator PI106 by decomposing it into two radicals PI*106*, at least one of which remains attached to the polymer silicone network 101. Thus, the immobilized PI106 has a low effect in inducing the chain polymerization process and is therefore far less likely to induce undesirable power fluctuations. Some LAL100s with such immobilized PI106 may exhibit history dependence, which needs to be addressed. In some control designs, irradiation patterns can be developed to correspond to different irradiation histories. 【0089】 (11) In other embodiments of LAL100, power fluctuations are prevented by not utilizing the photoinitiator PI106 at all. In such LAL100, polymerization of the MM mobile macromer 104 is directly induced by a two-photon or multi-photon process. Initiating such a process often requires irradiation of a higher intensity. Therefore, in such LAL100, UV irradiation can be delivered by a laser, possibly in a scanning motion with tight focus. If two 500 nm wavelength photons from such a laser collide with the mobile macromer MM104 quickly and successively, the polymerization chemical reactions of types (1) and (2) can be directly induced in MM104. This process is otherwise induced by a single 250 nm wavelength UV photon to compensate for losses. In contrast to the processes described above, in such LAL, the equivalent of the PI* radical 106* is never generated, and therefore no corresponding induced power fluctuation occurs after irradiation is stopped. 【0090】 This document contains many specific details, specifications, and numerical ranges, which should not be interpreted as limitations on the scope of the invention and claims, but rather as descriptions of features specific to particular embodiments of the invention. Specific features described in this document in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented separately or in any preferred partial combination in multiple embodiments. Furthermore, while features are described above as functioning in a particular combination, and may even be initially claimed as such, one or more features from a claimed combination may be removed from the combination in some cases, and the claimed combination may be directed towards another partial combination or a variation of a partial combination.

Claims

[Claim 1] Light-adjustable lenses (LAL), A polymer silicone network implanted with a mobile macromer, a non-switchable UV absorber, and a photoinitiator, Includes a front protective layer containing a switchable UV absorber, LAL activates a photoinitiator that induces polymerization of mobile macromers, and the light power of LAL can be adjusted by shaping irradiation, thereby changing the light power of LAL. LAL can accommodate oxygen concentrations in the range of 0.5 to 20 ppm. A photo-tunable lens (LAL) in which a photoinitiator is immobilized on a polymer silicone network. [Claim 2] The phototunable lens according to claim 1, wherein the shaping irradiation activates the photoinitiator by breaking it down into two radicals, at least one of which remains attached to the polymer silicone network. [Claim 3] A photoinitiator can become an activated photoinitiator when it absorbs UV photons. The light-adjustable lens according to claim 1, wherein the activating photoinitiator can activate the mobile macromer by activating the terminal groups of the mobile macromer. [Claim 4] The light-adjustable lens according to claim 3, wherein the activating terminal group of a mobile macromer can form a bond with a second mobile macromer, thereby activating the terminal group of the second mobile macromer. [Claim 5] The light-adjustable lens according to claim 3, wherein a low-activity photoinitiator derivative is produced by the reaction of an activated photoinitiator with oxygen. [Claim 6] The reaction between the activated mobile macromer and oxygen generates a low-activity compound. The light-adjustable lens according to claim 3, wherein LAL contains a radical scavenger that reacts with a low-activity compound to convert the low-activity compound into an inactivating compound. [Claim 7] The light-adjustable lens according to claim 1, wherein the switchable UV absorber is selected from the group consisting of azobenzene, azoaromatic compounds, diazenes, azopyrazole, dienylethene, flugicide, azulene, spiropyran, ethene aromatic compounds, macromers of these compounds, polymers of these compounds, compositions containing one of these compounds, compositions containing one of these compounds as a side chain, compositions containing one of these compounds as a main chain having a side chain, nanoparticle-like substances bonded to one of these compounds, 4-methoxyazobenzene, indazole, allylated azobenzene having various spacer bonds, phenylazopyrazole, vinylphenylazopyrazole, and stilbene. [Claim 8] The light-adjustable lens according to claim 1, wherein the front protective layer includes a non-switchable ultraviolet absorber. [Claim 9] A light-adjustable lens according to claim 1, comprising a radical scavenger or an antioxidant. [Claim 10] The light-adjustable lens according to claim 1, wherein the mobile macromer is monofunctional. [Claim 11] The optically adjustable lens according to claim 1, wherein the mobile macromer is sterically hindranced. [Claim 12] The photo-adjustable lens according to claim 1, wherein the photoinitiator is switchable between a protected state and an activatable state. [Claim 13] The phototunable lens according to claim 1, wherein the chemical composition, concentration and reaction rate of the silicone network, mobile macromer, switchable and non-switchable ultraviolet absorbers, and photoinitiator are such that the slope of the time-dependent power adjustment curve doubles or more after time t(activate) during the phototuning procedure, and t(activate) is in the range of 3 seconds to 100 seconds. [Claim 14] The photo-tunable lens according to claim 1, wherein the photoinitiator is immobilized on a polymer silicone network.

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