Eye Flashcards
Sclera
it’s a tough outer coat that protects the entire eyeball
Choroid
It’s a layer of the eye ball
It contains blood vessels that nourish the ineer parts of the eyeball
Cornea
It’s the front portion of the eye.
It bulges outside
Light enters the eye through the cornea
Iris
It is a dark muscular diaphragm located just behind the cornea.
It regulates the amount of light entering the eye by adjusting the size of the pupil.
Pupil
It is a hole in the middle of the iris.
Size of the pupil decreases or increases depending upon the intensity of light entering the eye
Eg. Looking at the sun would make your pupil decrease in size.
Eye lens
It is made up of a transparent jelly like substance. Which is made up of proteins.
It is held in position by ciliary muscle and suspensory ligaments.The ciliary muscle and suspensory ligaments adjust the vocal length of the eye so that we can see distant and nearby objects clearly.(accommodation
Aqueous humor
It is a viscous liquid filled in the area between the cornea and eye lens.
It prevents the eye from collapsing due to changes in atmospheric pressure.
Retina
It is a delicate membrane having a large number of light sensitive cells.
The light sensitive cells get activated upon illumination and generate electric signals.
The light sensitive cells are of 2 types
1)Rods: Cells that respond to the intensity of light.
2)Cones:Cells that respond to the color of objects
Macula
A tiny area in the Retina that is responsible for clear and sharp vision. There is a tine depression inside the Macula (fovea centralis) Here maximum cones are present.
An inverted real image of the object is formed on the retina
The electric signals generated by the cells are sent to the brain through the optic nerve.
Vitreous humor
It is a jelly like substance filled in between the retina and the eye lens.
It helps in maintaining the shape of the eye.
Blind spot
It is a small region in the retina where the optic nerve enters the eye.
It is insensitive to light Hanse it’s called the blind spot.
