Which structures in the retina host photoreceptors for vision?

• A. Retina photoreceptors: rods, cones, and ipRGCs
• B. Optic nerve
• C. Cornea
• D. Sclera

Answer: (A)

Photoreceptors are the light-detecting cells located in the retina. The main image-forming cells are rods and cones: rods enable vision in dim light and peripheral vision, while cones provide high-acuity, color vision in bright light. In addition, intrinsically photosensitive retinal ganglion cells (ipRGCs) are also photoreceptive and reside in the retina; they respond to light to regulate non-image-forming functions like pupil size and circadian rhythms, and they can influence retinal signaling as part of vision. The optic nerve, cornea, and sclera do not contain photoreceptors. So, the retina houses photoreceptors that include rods, cones, and ipRGCs.