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Lens Materials & Coatings
Ultraviolet / Other Coatings

UV 400: A method of specially treating ophthalmic lenses so that most of the ultraviolet wavelengths ranging from approximately 280 - 400 nm will be absorbed by the lens.

The range of visible light falls between about 390 - 750 nm as indicated above. However, wavelengths which actually reach the retina fall between 380 and 1400 nm, and, if not absorbed by the anterior portion of the eye, we would be able to perceive wavelengths as short as 300 nm.

Certain wavelengths are absorbed selectively by various parts of the eye. For example, wavelengths between 250 - 300 nm are absorbed by the cornea. While wavelengths which fall between 380 - 1900 nm pass through the crystalline lens, the vitreous absorbs all wavelengths longer than 1400 nm thus preventing them from reaching the retina.

Since the cornea absorbs ultraviolet light shorter than 300 nm, overexposure to these wavelengths can result in inflammation of the cornea and conjunctiva. Color changes in the crystalline lens which may contribute to the development of cataracts, may result when the eye is exposed to large quantities of ultraviolet light between 300-400 nm.


Anti-reflection Coating: A thin clear film applied to a lens surface which serves to reduce unwanted reflections and at the same time increase the amount of light that passes through the lens to the eye.

Scratch Resistant Coating: Since a disadvantage of plastic lenses has been their tendency to scratch more readily than glass, lens manufacturers have developed some excellent coatings which significantly increase resistance to scratching.

Edge Coating: A color coating applied to the edge of higher minus lenses which matches the color of the frame. When used properly, it tends to camouflage the thick edge of the lens and at the same time minimizes the concentric circles which can result from reflections off the lens edge.

Mirror Coating: A coating applied to the front surface of a lens through a vacuum process which causes the lens to assume properties similar to a two way mirror.


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