The Eye

Question 1

What is binocular vision?

Answer 1

When an organism has two eyes, which gives them 3D vision (depth perception)

Question 2

What is the socket of the eye called?

Answer 2

The Orbital Cavity

Question 3

Human eye specs

Answer 3

Fluid filled ball (2.5cm diameter)
Focuses light energy on the receptors of the retina

Question 4

What are the three layers in the eye?

Answer 4

The Sclera
The Choroid Layer
The Retina

Question 5

Sclera specs

Answer 5

Outer protective layer of the eye that maintains shape (white of your eye - no blood vessels)
Cornea - the transparent past of the sclera at the from of the eye that bends light rays into the eye

Question 6

Choroid Layers specs IPC

Answer 6

Middle layer (under the sclera); full of BVs for nourishment & contains melanin (dark pigment) that stops light from scattering
Absorbs stray light not detected by photoreceptors
Iris - (coloured part) round muscle surrounding the pupil. Regulates amount of light that enters the eye
Pupil - opening for light to enter inner eye (hole in the iris)
Ciliary Muscles - changed the shape of the lease in order to focus

Question 7

Retina specs

Answer 7

Inner layer
Contains light sensitive cells that turn the light into an impulse
Rods - Photoreceptors that are sensitive to dim light
Cones - PRs that are sensitive to different wavelengths of light (colour)
Fovea Centralis - contains a high density of rods and cones and provides acute (sharp) vision (near the back of the eye)
Most sensitive part of the Retina

Question 8

Pathway of the Nerve Impulse RBOTOV

Answer 8

Rods and Cones in Retina
Bipolar cells
Optic Nerve cells
Thalamus
Occipital lobe (visual cortex or cerebrum)
Visual association area of cerebrum

Question 9

Other structures of the eye LHO

Answer 9

Lens
Humours
Optic Nerve

Question 10

Lens

Answer 10

Focuses light rays onto the Fovea Centralis

Question 11

Humours

Answer 11

Aqueous Humour
Maintains shape of cornea, providing oxygen & nutrients ( in front of lens, behind cornea)
Vitreous Humour
Helps maintain the shape of the eyeball and supports the surrounding cells (behind lens) by putting pressure on the eye

Question 12

Optic Nerve

Answer 12

Carried electrochemical impulses from the eyes to the Occipital Lobe of the brain (collection of neurons that send impulses to occipital lobe)

Question 13

What is the Blind spot in the eye?

Answer 13

The area at the back of the eye where there are no cones or rods

Question 14

Acuity

Answer 14

A measurement of sensory perception
An acuity level is the amount of support one needs

Question 15

Accomodation

Answer 15

The ability the eye has to change the shape of the lens to make sure light is focusing on the right place, so we can focus on what we are looking at

Question 16

Adaptation

Answer 16

The ability of the Retina of the eye to adjust to different levels of light

Question 17

What is Myopia and Hyperopia?

Answer 17

Nearsightedness and Farsightedness, respectively

Question 18

What is an Astigmatism?

Answer 18

When the lens has a defect or a dent which prevents light from hitting it properly

Question 19

How does the eye focus

Answer 19

Light passes through the cornea and pupil & the iris controls how much light gets into the eye
Next, light passes through the lens, where it is focused on the retina, where light gets turned into impulses as it interacts with cones, rods and fovea centralis
From the Retina, the signals travel to the optic nerve to the brain, where the occipital lobe processes what we are looking at