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Flashcards in The Eye Deck (29):
0

Cornea

Front part of the sclera which is clear, helps to refract and focus light

2

Suspensory ligament

Ligaments connecting the ciliary muscle and the lens hold lens in place

3

In bright light the pupil...

Constricts. Circular muscles contract, radial muscles relax. Prevents too much light entering eye and damaging it.

4

The eye is a

Sense organ

5

Fovea (yellow spot)

Area dense with cones. Produces a detailed image

7

Ciliary muscle

Ring of muscle connected to lens via suspensory ligaments. Helps change the shape of the lens

8

Optic nerve

Part of CNS. Transmits nerve impulses from retina to brain to create image

9

Choroid

Black pigment which absorbs light. Prevents light reflecting inside the eye

10

Rod

Photoreceptor in retina used for dim light vision, only shows black and white. Detects intensity of light.

11

In low light the pupil

Dilates. The circular muscles relax and the radial muscles contract

12

Cone

Photoreceptor in retina. Detects colour. Do not work in low light.

13

There are 3 types of cone cell in the retina. They detect which colours of light?

Red, blue, green

14

2 types of receptor cell

Rods and cones

15

Retina

Light sensitive inner layer of eye which contains photoreceptors

17

Retina

Internal lining at back of eye contains rods and cones which respond to light.

18

Why is the pupil black?

Because there is no light escaping from the inside of the eye

19

What stimulus does the eye detect?

Light

20

Receptor cells in the eye where are they and what do they di

-at the back of the eye in the retina
-sensitive to light and transmit impulses to the CNS
When light falls on these cells they send off nervous impulses

21

2 types of receptor cell in eye

Cones - sensitive in high light intensities and allow us to see in colour (in the fovea)
Rods - sensitive in low light intensities and produce images in black and white

22

Sclera

Tough, white outing coating which protects the eye

23

Iris

Flexible disc of tissue which can change its shape in order to let more light into the pupil
Controls light entering eye

24

Pupil

Hole in centre of iris which lets in light to rest of eye

25

Lens

A transparent structure which is flexible and can change its shape in order to focus on an image

26

Suspensory ligament

A ring of fibres which holds the lens in place

27

Ciliary muscle

Ring of muscle connected to lens via suspensory ligament
Controls accommodation (focusing)

28

Accommodation

The reflex that makes the eye focus on an object by changing the shape of its lens

29

How do we see things?

Light reflected from an object is refracted by the cornea and the lens forming an upside down image on the retina

30

Why can't we see colours so well in the dark

When there is little light, the cones do not work so we find it difficult to tell what colour things are

31

What is the conjunctiva

Layer covering the cornea and sclera that helps to lubricate the eye