Optical

adjective

1. Of, or relating to sight; visual.

   "Strabismus is an optical defect."

2. Designed to assist or enhance sight

   "A microscope is an optical instrument."

3. Of, or relating to optics.

   "Refraction is an optical effect."

4. Of, or relating to visible light.

   "Optical telescopes don't work when it is cloudy."

5. Incorporating light-sensitive devices.

   "An optical switch opens the door automatically."