Which structure is the light-sensitive layer at the back of the eye?

Which structure is the light-sensitive layer at the back of the eye?

• A. Cornea
• B. Sclera
• C. Retina
• D. Iris

Answer: (C)

The retina is the light-sensitive layer at the back of the eye. It houses photoreceptor cells—rods and cones—that detect light and color and convert it into electrical signals. Light travels first through the cornea and lens to be focused onto this layer, and then the photoreceptors trigger signals that travel through retinal neurons to the optic nerve and onward to the brain for interpretation. The other structures have different roles: the cornea is the clear front surface that helps focus light, the sclera is the tough white outer coating, and the iris controls the amount of light entering by adjusting pupil size.

The retina is the light-sensitive layer at the back of the eye. It houses photoreceptor cells—rods and cones—that detect light and color and convert it into electrical signals. Light travels first through the cornea and lens to be focused onto this layer, and then the photoreceptors trigger signals that travel through retinal neurons to the optic nerve and onward to the brain for interpretation. The other structures have different roles: the cornea is the clear front surface that helps focus light, the sclera is the tough white outer coating, and the iris controls the amount of light entering by adjusting pupil size.