Eye

Question 1

Retina

Answer 1

Where the rod and cone cells are located. Contains light receptor cells

Question 2

Rods

Answer 2

Detect light intensity

Question 3

Cones

Answer 3

Detect colour

Question 4

When there is a near object

Answer 4

• Ciliary muscle contracts
• suspensory ligaments loosen
• lens thickens
• so light is refracted STRONGLY

Question 5

When there is a far object

Answer 5

• Ciliary muscles relax
• susepnsory ligaments tighten
• lens becomes thinner
• so light refracts less

Question 6

Short sightedness

Answer 6

• Myopia

- rays of light focus in front of the retina

Question 7

Long sightedness

Answer 7

Hyperopia

• where rays of light focus behind the retina

Question 8

How can myopia be fixed

Answer 8

• using a concave lens to focus light on retina

Question 9

How can hyperopia be fixed

Answer 9

• using a convex lense to focus light on retina

Question 10

Treatments for myopia or hyperopia

Answer 10

• Hard and soft contact lenses (good for sport, comfortable)
• laser eye surgery (can change shape of cornea, which CHANGES HOW IT REFRACTS LIGHT ONTO THE RETINA)
• lens replacement surgery (replaces lens of eye with plastic artificial lens)

Question 11

Laser eye surgery for myopia

Answer 11

• cornea is slimmed down, reducing refractive power

Question 12

Laser eye surgery for hyperopia

Answer 12

Cornea shape is thickened so refractive power is increased

Question 13

Risks and positives of hard contact lenses

Answer 13

• can be more uncomfortable
• causes damage if broken
• requires cleaning
• far more durable
• less environmentally damaging

Question 14

Risks and positives of soft contact lenses

Answer 14

• more comfortable than hard contacts
• environmentally damaging
• higher risk of infection

Question 15

Pupil reflex in dim light

Answer 15

• radial muscles of iris contract
• circular muscles of iris relax
• dilated pupil (more light enters eye)

Question 16

Pupil reflex in bright light

Answer 16

• radial muscles relax
• circular muscles contract
• pupil is constricted (less light enters the eye)

Question 17

Cornea

Answer 17

Transparent lens that refracts light as it enters eye

Question 18

Iris

Answer 18

Controls how much light enters the pupil

Question 19

Lens

Answer 19

Transparent disc that can change shape to focus light onto the retina

Question 20

Retina

Answer 20

Contains light receptor cells

Question 21

Optic nerve

Answer 21

Sensory neurone that Carries impulses between eye and brain