Variable-Focus Lens Autofocus Actuation for Vision Accommodation
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Solution Overview
Problem
Current ophthalmic assemblies for accommodating vision, such as those used in cataract surgery or for presbyopia, often result in the need for glasses due to limitations in mechanical motion or energy efficiency, and existing lenses may not effectively correct vision across a wide range of disorders or accommodate for patients with reduced ciliary muscle function.
Innovation Solution
An ophthalmic assembly comprising a variable-focus lens, an autofocus system, a processor, and an actuator, which adjusts the lens's dioptric power based on distance parameters determined by the autofocus system, allowing for accommodation without glasses and compatibility with existing intraocular lenses, even in patients with reduced ciliary muscle function.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multifocal lenses or lenses with extended depth-of-focus are used to re-create accommodation, then vision at varying distances is improved, but light intensity is distributed across multiple focal points causing energy loss and adverse effects such as halos, glares or ghost images
Solution Approach 1:
The patent employs a variable focus lens that dynamically changes its focal length based on the distance of the object being viewed. The lens transitions from a static multi-focal design to a dynamic single-focal design, where the focal point moves continuously to match the object distance, eliminating light distribution across multiple fixed focal points and thereby reducing energy loss and visual disturbances.
Solution Approach 2:
The patent changes the focal length parameter of the lens continuously rather than using fixed discrete focal points. By varying the focal length dynamically according to object distance, the system maintains concentrated light intensity at a single focal point while adapting to different viewing distances, thus avoiding the energy dispersion inherent in multifocal lens designs.
2Adaptability or versatility
If accommodative lenses based on mechanical motion driven by the ciliary muscle are used, then accommodation function is restored, but the ciliary muscle loses its capability with age due to previous conditions (cataract, presbyopia, etc.) and capsular fibrosis, often not allowing enough motion to compensate the expected level of accommodation
Solution Approach 1:
The patent replaces the unreliable biological mechanical system (ciliary muscle) with an artificial actuation system. The variable focus lens is driven by an actuator that can be controlled independently of the ciliary muscle's degraded function, ensuring reliable accommodation even in patients with age-related or disease-related muscle impairment.
Solution Approach 2:
The patent introduces an intermediate actuation mechanism between the control system and the lens. This intermediary actuator translates control signals into lens deformation or movement, bypassing the compromised ciliary muscle entirely and providing a reliable transmission of the accommodation command regardless of the muscle's condition.
3Adaptability or versatility
If lenses with large width are used to cover a great range of disorders, then the extent of vision disorders that can be corrected is improved, but the lens periphery receives little light depending on the size of the iris, which is a severe drawback if the lens periphery is used to host peripheral devices
Solution Approach 1:
The patent uses a variable focus lens with a relatively small aperture that dynamically adjusts its focal length rather than relying on a large static lens aperture. This dynamic focusing capability allows a smaller lens to cover a wide range of vision disorders by changing focus rather than by having multiple fixed focal zones across a large aperture, thereby ensuring adequate light intensity across the entire lens surface including the periphery.
4Adaptability or versatility
If technology requiring great amount of energy is used in a small available size, then the functionality of the ophthalmic assembly is improved, but the energy consumption is not compatible with the constraints linked to the small available size
Solution Approach 1:
The patent extracts the high-energy components (power source and complex control electronics) from the intraocular lens assembly itself. The variable focus lens is controlled by a low-energy actuator that receives simple control signals from external or minimally integrated sources, thereby reducing the energy burden on the implanted device while maintaining full functionality.
Solution Approach 2:
The patent employs passive or low-energy mechanisms for lens actuation, such as shape memory materials, electroactive polymers, or piezoelectric elements that require minimal energy input. These self-actuating or low-power materials enable the lens to change focus with minimal energy consumption, making the system compatible with the limited power availability in an implantable device.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables accommodation similar to a healthy eye, correcting vision across various distances without glasses, and maintaining functionality even in patients with compromised ciliary muscle function, while being energy-efficient and adaptable to individual eye characteristics.
Implementation Method 1
an autofocus lens system configured to cause light passing through at least a part of the autofocus lens system from the target object upon which the user's gaze falls to form an image
Implementation Method 2
a variable-focus lens having a variable dioptric power; an actuator configured to cause the dioptric power of the variable-focus lens to vary
Data Source
AI summary
An ophthalmic assembly for implantation in an anterior chamber of an eye of a patient to provide accommodation of the vision to said patient comprises a variable-focus lens and an actuator for modifying the focal length of the variable-focus lens. The ophthalmic assembly comprises an autofocus system configured to determine a distance parameter of an object that the patient's eye is looking at; a signal processing unit arranged to convert said distance parameter into a focal length value of the variable-focus lens; and an actuator control unit configured to control the actuator as a function of the focal length value received from said signal processing unit. A method for accommodating the vision of a patient using an opthamalic assembly is also disclosed.