Marked contact lens bearing optical marking element

Abstract

The marked contact lens has at least one microlens optical marking element integrally formed on the surface of the contact lens in a peripheral area thereof. The microlens marking elements are of shallow depth, yet focus light to appear as relatively bright (or dark) marking objects. The marking elements may be spherical or cylindrical microlens formations. The dimensions of the microlenses are chosen so as to avoid any irritation when worn by the user. The marking objects identify the lens source, proper orientation or, in the case of soft lenses, inversion.

Description

FIELD OF THE INVENTIONThe present invention relates to a marked lens, and more particularly to a marked contact lens and a method of making same.BACKGROUND OF THE INVENTIONDuring the past 10 to 15 years, contact lenses have tended to replace glasses for correcting vision problems. These days, an entire industry exists for contact lens manufacturing and retailing.One of the problems associated with contact lenses is marking the lens in order to allow the users to wear them properly, in the right position. Some lenses have to be worn in an "upright" orientation while soft lenses must be worn without inverting them, i.e. wearing them inside-out. Generally, identification and orientation marks applies to all kinds of contact lenses.Various methods of contact lens identification are known in the prior art. One method is printing a visible mark on the periphery of the lens. However, this method is not suited for wet molded soft lenses since the printing must be performed on a dry surface ...

AI Technical Summary

Benefits of technology

For clarity, this text uses the term "surface orientation" to designate the orientation of a lens with its concave surface toward the wearer's eye, as it should be worn. The main object of the present invention is to provide an easy information to the lens user concerning the right surface orientation of the lens, before the lens is applied on the eye's surface.

According to the invention, instead of marking contact lenses as in the prior art by adding a color on them such as by printing or engraving a mark on them, the present invention uses microstructure surface variations, such as dot or cylindrical microlenses, having the form of concave or convex semi-spheres or semi-cylinders (the cross-section may also be elliptical or aspheric), which are applied on the surface of the contact lens in order to provide identification and orientation marks for allowing the user to wear the lenses in the adequate position. The surface variations are small and their surface is smooth and highly polished therefore these microlenses do not attract and do not retain proteinaceous and other deposits. Furthermore, these microlenses are not felt by the wearer's eyelid. The dimensions of the microlenses are chosen so as to avoid any irritation when worn by the user. However, when removed and held up toward a light source, they permit to the user to clearly see them, thus providing information on the right position they have to be worn in.

In another preferred embodiment of the invention, the optical elements may be located on a single side of the lenses or on both sides of the lenses. In the latter case, the optical elements may be even smaller in depth or height if they are applied in conjunction to one another, one on each face of the lens, thus superposing the optical effect seen by the human eye when looking to the lens toward a light source.

Problems solved by technology

One of the problems associated with contact lenses is marking the lens in order to allow the users to wear them properly, in the right position.

However, this method is not suited for wet molded soft lenses since the printing must be performed on a dry surface and the lenses are never in a dry state.

Furthermore, the dark mark printed on lenses may be too visible, so observers may even see the mark when the lens is worn by a person.

However, this surface is necessarily rough and may be felt by the wearer, thus producing discomfort.

However, this method cannot be employed for wet molded soft contact lenses.

It is also time-consuming and expensive.

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