Used in photochromic materials, especially in ophthalmic lenses and optical coatings. The compound undergoes reversible structural changes when exposed to UV light, enabling automatic darkening in response to sunlight. It is incorporated into polymer matrices to create lenses that transition between clear and tinted states, providing comfort and UV protection. Its methacrylate group allows covalent bonding into acrylic-based systems during curing, ensuring durability and long-term performance without leaching. Also explored in smart windows and light-responsive sensors due to its fatigue resistance and fast switching speed.