Sunglasses serve a greater purpose than simply reducing sunlight. Beyond visual comfort, they provide crucial protection and optimize visual function, especially for the visually impaired. It's not just about light…
Sunglass lenses should be able to:
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: (more…)
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). (more…)
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. The darkness of the tint does not indicate it’s capability to protect against harmful UV light.
While you may think that sunglasses are just glasses with a tint, but protecting the eyes requires more than just a tint. The tint decreases the amount of light that reaches your eyes. 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. (more…)