ExpertSun change color reversibly in the absence and presence of UV. Developed from new polymerizable naphthopyran derivatives, they provide a good compromise between color intensity and speed of coloring and fading. Moreover, their structural change in the excited form is not disturbed by the surrounding polymer matrix. Therefore, they exhibit good fatigue resistance.

Naphthopyran derivatives, used at very low proportions, can be co-polymerized with many monomers and provide photochromic properties to both hydrophilic and hydrophobic polymers. The flexibility of this technology opens up interesting prospects for many applications.

Photochromic polymer uses

Numerous applications in the ophthalmic field have been developed around these molecules: darkening of sunglasses lenses, color change of contact lenses… allowing to protect the retina against damage caused by ultraviolet radiation.
PolymerExpert has chosen to integrate these photochromic polymers into intraocular lenses in order to provide visual comfort to cataract patients. With age, the crystalline lens loses its transparency and becomes slightly yellow. During cataract surgery, this lens is replaced by a totally transparent implant. PolymerExpert proposes to limit the disruption of this change through implants that adapt to the intensity of ultraviolet radiation. These products will be marketed by PolymerExpert’s subsidiary Innolens.

Photochromic polymers can also be used for quality control or safety systems.