C06 - The Eye and Vision

Question 1

What does the Visual System contain (3)?

Answer 1

• The Eyes.
• The Optic Nerve.
• Visual Cortex.

Question 2

What is the function of the Optic Nerve?

Answer 2

Connects the Eyes to the Visual Cortex.

Question 3

What is the function of the Visual Cortex?

Answer 3

Responsible for processing information received from the Eyes.

Question 4

True or False. 60% of all sensory information is processed by the brain is visual information?

Answer 4

False. 70%.

Question 5

The outside of the Eye is covered in a smooth, very tough layer of white tissue called?

Answer 5

Sclera.

Question 6

‘____’ allows light to enter the Eye and fall on the lens via a hole in the ‘____’ called the ‘____’ (3)?

Answer 6

• Cornea.
• Iris.
• Pupil.

Question 7

What is the function of a Cornea?

Answer 7

Controls and focuses the amount of light entering onto the Retina.

Question 8

What is an Iris and its function (2)?

Answer 8

• A structure surrounding the Pupil.

- Contracts and expands to light levels, thus altering the size of the Pupil.

Question 9

Name two types of Photoreceptors and their functions (2)?

Answer 9

• Highly Light Sensitive Rods = Can’t detect colour.

- Less Sensitive Cones = Can detect colour.

Question 10

Name two functions of the Cones?

Answer 10

• Responsible for detecting colour.

- Used for Daylight Vision.

Question 11

What is the function of the Rods?

Answer 11

Used for Night Vision.

Question 12

What is the Fovea?

Answer 12

Located in the central region of the Retina and is densely packed with Cones.

Question 13

Define Vision?

Answer 13

The process of taking signals from the Eyes and interpreting them in the Brain.

Question 14

Name four factors affecting Visual Acuity?

Answer 14

• Hypoxia.
• Smoking.
• Alcohol.
• Short/Long Sightedness.

Question 15

Why do we have Blind Spots?

Answer 15

Because there are no Rods and Cones in the Optic Disc.

Question 16

What is Empty Field Myopia?

Answer 16

When the Eye resumes a default focus of 1 or 2 metres, due to a featureless field of Vision.

Question 17

How can we make objects more detectable at night?

Answer 17

By looking at them slightly off-centre.

Question 18

What is the term and definition for Short Sightedness (2)?

Answer 18

• Myopia.

- The inability to focus on distant objects.

Question 19

What is the term and definition for Long Sightedness (2)?

Answer 19

• Hyperopia/Hypermetropia.

- The inability to focus on near objects.

Question 20

Define Astigmatism?

Answer 20

Reduce in optical power of the Cornea/Lens.

Question 21

Define Presbyopia?

Answer 21

A form of Long Sightedness commonly developed with age.

Question 22

Define Cataracts?

Answer 22

Clouding of the lenses.

Question 23

Define Glaucoma?

Answer 23

A disease in which the internal pressure of the eye increases.