Flashcards in The Eye Deck (29):
Front part of the sclera which is clear, helps to refract and focus light
Ligaments connecting the ciliary muscle and the lens hold lens in place
In bright light the pupil...
Constricts. Circular muscles contract, radial muscles relax. Prevents too much light entering eye and damaging it.
The eye is a
Fovea (yellow spot)
Area dense with cones. Produces a detailed image
Ring of muscle connected to lens via suspensory ligaments. Helps change the shape of the lens
Part of CNS. Transmits nerve impulses from retina to brain to create image
Black pigment which absorbs light. Prevents light reflecting inside the eye
Photoreceptor in retina used for dim light vision, only shows black and white. Detects intensity of light.
In low light the pupil
Dilates. The circular muscles relax and the radial muscles contract
Photoreceptor in retina. Detects colour. Do not work in low light.
There are 3 types of cone cell in the retina. They detect which colours of light?
Red, blue, green
2 types of receptor cell
Rods and cones
Light sensitive inner layer of eye which contains photoreceptors
Internal lining at back of eye contains rods and cones which respond to light.
Why is the pupil black?
Because there is no light escaping from the inside of the eye
What stimulus does the eye detect?
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
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
Tough, white outing coating which protects the eye
Flexible disc of tissue which can change its shape in order to let more light into the pupil
Controls light entering eye
Hole in centre of iris which lets in light to rest of eye
A transparent structure which is flexible and can change its shape in order to focus on an image
A ring of fibres which holds the lens in place
Ring of muscle connected to lens via suspensory ligament
Controls accommodation (focusing)
The reflex that makes the eye focus on an object by changing the shape of its lens
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
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