Epolin has developed dye formulations that provide protection from the suns harmful UV and NIR radiation. While most sun lenses protect against UV very few provide near infrared protection.
If your sun lens fails to block NIR light it can be absorbed by your cornea. This can cause irritation and redness. More importantly, a good portion of NIR radiation penetrates the ocular media and is focused on the retina at the rear of the eye. This leads to photochemical light damage that cannot be felt because there are no pain sensors in the retina.
Epolight 7530 and Epolight 7539 can be used in polycarbonate sunglass lenses used for children and adults. These dye formulations can also be used in lenses for people already suffering from macular degeneration. Each formulation blocks most of the NIR radiation and all the UV radiation.
Epolight 7530 provides a grey sun lens and provides good color recognition. Epolight 7539 provides a bronze sun lens which provides excellent visual contrast.
Please refer to the product datasheets for more information about these dyes.