B3 the eye

Question 1

Cornea

Answer 1

refracts light into the eye

Question 2

Iris

Answer 2

controls how much light enters the pupil

Question 3

Lens

Answer 3

also refracts light, focusing it on the retina

Question 4

Ciliary Muscles

Answer 4

attached to suspensory ligaments, alter shape of the lens

Question 5

Retina

Answer 5

is light sensitive, covered in receptors called rods and cones.

Question 6

Rods

Answer 6

can see well in dim light but not color.

Question 7

Cones

Answer 7

can see color but struggles in dim light

Question 8

Optic Nerve

Answer 8

carries nerve impulses from the receptors to the eye.

Question 9

what happens when you see distant objects

Answer 9

ciliary muscles relax so suspensory ligaments tighten.

This causes the lens to become less rounded so less light is refracted.

Question 10

what happens when you see near objects

Answer 10

ciliary muscles contract so suspensory ligaments relax . This causes lens to widen and become more rounded allowing for more light to be refracted.

Question 11

what is it called when you are long sighted

Answer 11

Hyperopia

Question 12

what is it called when you are short sighted

Answer 12

Myopia

Question 13

hyperopia is when

Answer 13

you cant focus on near objects
because the lens is the wrong shape and doesn't bend light enough 
or 
eyeball is too short
images focus behind the retina

Question 14

how to treat hyperopia

Answer 14

using a convex lens that bends light more so the image forms at the retina.

Question 15

myopia is when

Answer 15

you can focus on distant objects 
because the lens is the wrong shape and refracts light too much.
or 
eyeball is too long
images focus before the retina.

Question 16

how to treat myopia

Answer 16

corneal surgery
or
concave lens that bends light less.