CRIZAL E-SPF

E-SPF

The Eye-Sun Protection Factor (E-SPF) is an international index developed by Essilor Research & Development to certify the overall UV protection provided by a lens. It is an objective rating system that can rate any lens for daily eyewear and for sunglasses. The pattern followed by the E-SPF rating system to rate the lens is inspired by the cosmetic industry standard of UV protection. This means the higher the E-SPF, the better the UV protection. It follows an impartial measurement protocol that has been endorsed by an independent third party.

Why is the E-SPF required? The commonly used "100% UVA/UVB" label does not provide complete information about the overall UV protection of a lens. In fact, the UV radiations reflected on the back of a lens are not taken into account by the existing labels. It is to be noted that the UV radiations reflected from the back of a lens represent 50% of all UV received into an eye. Contrary to the existing labels, the E-SPF index integrates UV protection provided by both the sides of a lens.

How does the E-SPF work? The Eye-Sun Protection Factor is used to rate effectiveness against the ultraviolet radiations, which means the E-SPF value is directly proportionate to the level of UV protection. For instance, wearing a lens with an E-SPF value of 25 means your eye is 25 times better protected than an eye without a lens.

As all the lenses are not equal in terms of UV protection, it is important for you to get the right protection for your eyes. You can use the E-SPF to compare the levels of UV protection provided by the different kinds of eyewear including clear, photochromic and sunglasses. Note: Ask for advice from your Eye Care Professional. The E-SPF values vary from 2 to a maximum of 25 for daily eyewear lenses with the perfect transparency and up to 50+ for sun lenses based on the measurements made till April, 2012.

So, keep your eyes open while selecting eyewear lenses for yourself and look for the lens with the highest E-SPF value.