The Eye

The eye ball is roughly spherical and is held in place in a socket in the skull by six muscles.

• True

• False

The eyeball is rounded, so the cornea acts as a lens. It bends or reflects light.

• True

• False

The size of the ----- is determined by the iris, the contractile ring that is associated with eye color.

Answer explanation

pupil

Ciliary muscles surround the lens, relaxing to flatten it to image distant objects and contracting to ------ the lens to image close-up objects.

Answer explanation

thicken

Rods detect light and dark and help form images under ------ conditions.

Answer explanation

dim

----- are responsible for color vision. 

Answer explanation

Cones

When you focus clearly on an object, light strikes a region called the ------, yellow spot.

Answer explanation

fovea

By helping to focus light as it enters the eye, the ------ and the lens both play important roles in giving us clear vision.

Answer explanation

cornea

Farsightedness is a refractive error that makes nearby objects look blurry. It happens when the shape of the eye makes light focus behind the retina.

• True

• False

• Nearsighted eye

• Farsighted eye

• Normal vision

Answer explanation

Nearsightness eye