What are the three types of receptor cells in the retina?

Rods and cones are the ones involved in actually seeing. Rods detect mostly black and white, though they might detect some blue. The cones are the color receptors, and they have 3 subtypes to detect long, medium, and short wavelengths of visible light.

There is a third type, photosensitive ganglion cells. They are important for entrainment and reflexive responses to the brightness of light..