Sense of Vision

Eye is surrounded by a protective cushion of ____

fat

How much fraction of eye is visible to us

1/6. (Diameter of eye is 1 inch and we can only see 1/6 of it)

_____ is the dominant sense in humans

Vision

____% of sensory receptors are in human eyes

70%

What is a Cornea?

Clear protective layer of eye

What is Iris?

Colored muscle that changes that amount of light that enters the pupil

What is lens?

Focuses light onto the retina

What is Retina?

Layer that contains photoreceptors

What is Optic Disc?

It's a point where retina enters the optic nerve

What is a choroid?

Vascular layer that assisting in protecting the eye

What is Sclera?

Opaque, protective layer

What does lenses do?

It changes shape to focus light onto the retina

What is Myopia?

Light is focused in front of the retina (Nearsightedness). Eyeball is too long.

What is Hyperopia?

Light is focused behind the lens. Eyeball is too short.

What color does rods distinguish?

Only black and white

What color does Cones distinguish

Colors. (ROYGBIV)

Where are Rods mostly found in the eye?

Thought the retina

Where are Cones found in the eye?

Highly concentrated at fovea. They are NOT present at periphery vision thus objects appear black and white when you see using periphery vision.

What are the four main parts of Retina?

Macula, Fovea, Optic Disc and Vessels

What is Macula

darker spot located at the posterior pole

What is Fovea?

Maximal visual acuity (most concentrated cones)

What is Optic Disc?

"Blind Spot" because there are no photoreceptor cells

What is the function of vessels in the eye?

Transfer blood

What is Contralateral processing?

Visual information is processed by the opposite side of the brain from which it enters, ex. right field of vision processed by left side of brain

What is cataract?

Clouding of lens due to build-up of proteins.

What is Glaucoma?

Occurs when there is a problem with drainage and intracellular pressure increases

What happens to eyeball when hyperopia occurs?

The eyeball gets short

What happens when eyeball when myopia occurs?

The eyeball gets long

What is Viterous?

Gel like material that fills the inside of your eye.

What is Retinal Detachment?

Shrinkage or contraction of the vitreous. Can also be caused by a blow the head or due to diabetes. This shrinkage can create tugging on the retina and a retinal tear, causing retinal detachment.