That preserved circuitry has created an opportunity for researchers to restore light sensitivity without replacing the damaged cells themselves. Even after photoreceptors are lost, much of the retinal network that normally carries visual information toward the brain remains functional. Researchers delivered them through injections into the eye, similar to other ophthalmic treatments, and through eye drops. Eye drops restore light responses in animalsThe strategy uses photopharmacology, a method that allows light to switch a drug’s activity on and off. Visual responses returned following injections into the eye and after the drugs were delivered topically as eye drops.