This type of photoreceptor cell allows humans to see gray tones in dim light while also providing us with peripheral vision.

A color-blind person has likely lost the ability of his or hers _______ to function properly.

This area of the retina has the highest concentration of cones.

This gel-like substance keeps the eye from collapsing inward.

This flexible, crystal-like structure helps focus light on the retina.

The choroid consists of an outer, pigmented layer and an inner, neural layer which is home to rods and cones.

The pupil is the circular opening in the iris through which light passes.

Eye movements are controlled by the abducens, oculomotor, and trochlear nerves.

We cannot see images formed on the optic disc (blind spot).

Cones are photoreceptor cells that allow us to see gray tones in dim light.

The ciliary body is a smooth muscle structure to which the lens is attached.