Essilor developed the Eye-Sun Protection Factor (E-SPF) as a new standard certifying the global UV protection of a lens
Whether a clear, photochromic or sunwear lens, E-SPF includes UV protection against both transmitted and reflected UV rays, so now you can be sure your patients get the best protection.
E-SPF is a ratio of UV irradiance that compares protection with and without a lens and has been established using a series of experimental measurements. The measurements and calculation have been endorsed by Karl Citek, OD PHD FAAO.
Just as the skin care industry adopted an index to identify levels of protection against ultraviolet rays for the skin, E-SPF has been developed to bring a new standard in UV protection provided by lenses. This will help you recommend the best level of UV protection to your clients. As the index used to rate skincare and sunscreen products efficiency, the concept for the consumer is a very simple one: the higher the E-SPF value, the better the level of protection.