The Eye

The __________ is the transparent structure behind the pupil that changes shape to help focus images on the retina.

Lens

A __________ is the adjustable opening in the center of the eye through which light enters.

Pupil

The __________ is the light-sensitive inner surface of the eye containing receptor cells and neurons for processing visual information.

Retina

The ring of muscle tissue that forms the colored portion of the eye is called the __________.

Iris

The process by which the eye’s lens changes shape to focus on near or far objects is called __________.

Accommodation

What is the term for the sharpness of vision?

Acuity

__________ is a condition in which nearby objects are seen more clearly than distant objects because distant objects focus in front of the retina.

Nearsightedness

What condition allows faraway objects to be seen more clearly than near objects?

Farsightedness

__________ are retinal receptors that detect black, white, and gray, necessary for peripheral and twilight vision.

Rods

__________ are receptor cells concentrated near the center of the retina that function in daylight and detect fine detail and color.

Cones

The optic nerve is formed by the converging axons of __________ cells in the retina.

Ganglion

What creates a 'blind spot' in the eye?

The point at which the optic nerve leaves the eye.

The __________ is the central focal point in the retina around which the eye’s cones cluster.

Fovea

Light energy strikes the rods and cones, producing __________ changes that generate neural signals.

Chemical

The chemicals produced by light energy in the retina activate __________ cells that then activate ganglion cells.

Bipolar

A deficiency in sharpness of vision is referred to as low __________.

Acuity

The __________ controls the size of the pupil opening, regulating the amount of light entering the eye.

Iris

During fetal development, part of the __________ migrates to form the eye.

Brain

The __________ is essential for peripheral vision and functions when cones do not respond.

Rods

What is the main difference between nearsightedness and farsightedness?

Nearsightedness causes distant objects to be blurry, while farsightedness makes near objects blurry.

Chemical changes in rods and cones generate __________ signals that travel to the brain.

Neural