Category Archives: Eyeglass TEchnology

Sunglass Technology: Putting It All Together

If you have read the other posts on Lens Technology, what you may have realized is that sunglasses are more than a tint used to decrease the amount of sunlight that gets to your eye.  While visual comfort is important, sunglasses are also about protection and optimizing visual function. It is not just about how much light is transmitted through the lens, but how the lens performs. Ideally, they should enhance vision. Here’s how: Continue reading Sunglass Technology: Putting It All Together

Protecting the Eyes: UV Light

Decreasing light levels with a tint may give a greater level of visual comfort, but may not offer enough protection against wavelengths of light known to be harmful to the sensitive tissues of the eye. Specifically, protection from the high energy, damaging, short wavelength UV light.  Lens materials such as plastic and poly carbonate have some UV absorbing capability (see Lens Materials). Continue reading Protecting the Eyes: UV Light

Protecting the Eyes: Tints

While you may think that sunglasses are just glasses with a tint, protecting the eyes requires more than just a tint.  The tint decreases the amount of light that reaches your eyes.  Tints not only vary in color, but also vary in transmissibility. The amount of light that is transmitted is the amount of light  allowed to pass through the lens. Generally, the darker the tint, the less light is transmitted (passed through) the lens. Someone who is outdoors and needs to decrease the brightness of sunlight, will choose a lens with low transmittance.  Keep in mind, the darkness of the tint does not indicate it’s capability to protect against harmful UV light. Continue reading Protecting the Eyes: Tints

Lens Technology: Anti-reflective Coating (Anti-Glare)

Anti-reflective coating is applied to the surface of the eyeglass lens to optimize vision by reducing glare. Ideally, it should be applied to both the front and back surface of the lens for maximum benefit. It serves several purposes: Continue reading Lens Technology: Anti-reflective Coating (Anti-Glare)

Lens Technology: Aspheric lenses

‘Aspheric’ refers to a type of lens design. It is recommended for those high powered reading and magnifying eyeglasses.  There is also an aspheric design for those who are very near-sighted and wear ‘coke-bottle’ lenses in their eyeglasses. You may also see hand-held and stand magnifying lens that are aspheric in design. Continue reading Lens Technology: Aspheric lenses

Eyeglass Technology: Lens Materials

You think that it should be simple: aren’t all eyeglass lenses clear plastic: Most are, but there are several types of plastic, each with features that differentiate them by how they function.   There are also glass lenses, which are only occasionally a first choice.

Once the eye doctor has written up a prescription for eyeglasses and you are sitting in front of the optician, he or she will begin asking you questions about lens-type preferences. The optician will often give suggestions as to the best lens material for you based on the prescription. They will usually educate the consumer as to the features that will be beneficial.  Here are the basic types of lens materials: Continue reading Eyeglass Technology: Lens Materials