The Structure of the Eye

What is the function of the eye?

To detect light and form images on the retina.

What is the cornea?

The transparent curved outer layer that refracts incoming light.

What is the function of the cornea?

To refract most of the light entering the eye.

What is the iris?

The coloured part of the eye containing muscles that control pupil size.

What is the pupil?

The opening through which light enters the eye.

What is the function of the pupil?

To allow light to enter the eye.

What is the lens?

A transparent structure that changes shape to focus light onto the retina.

What is the retina?

A layer at the back of the eye containing light-sensitive receptor cells.

What is the function of the retina?

To detect light and convert it into electrical impulses.

What is the optic nerve?

A nerve that carries electrical impulses from the retina to the brain.

What is the sclera?

The tough outer layer that protects the eye.

What is the function of the ciliary muscles?

To change the shape of the lens during accommodation.

What are suspensory ligaments?

Fibres that connect the lens to the ciliary muscles and control its shape.

What happens when light reaches the retina?

Photoreceptors detect the light, producing electrical signals.

What are rod cells?

Photoreceptors that are sensitive to low light levels but do not detect colour.

What are cone cells?

Photoreceptors that detect colour and fine detail in bright light.

Why are rod cells useful in dim light?

They are more sensitive to low light intensity than cone cells.

Why are cone cells important for colour vision?

Different cone cells respond to different ranges of visible wavelengths.

What is the blind spot?

The point where the optic nerve leaves the retina, containing no photoreceptors.

Why can the eye not detect light at the blind spot?

There are no rod or cone cells there.