The Eye Flashcards
(12 cards)
What is the organ of sight?
The eye is the organ of sight (root = opt/o or oculo or ophthalm/o) and the optic nerve is the sensory nerve of sight.
What is the shape and composition of the eyeball?
The eyeball is almost spherical in shape and is embedded in fat. It is composed of three layers: sclera, choroid, and retina.
What is the sclera?
The sclera is the tough outer fibrous coat forming the white of the eye. The front part is covered in conjunctiva, a membrane that also lines the eyelids.
What is the function of the cornea?
The cornea protects the eye and allows light to enter the eye.
What is the choroid?
The choroid is the middle coat containing blood vessels and the pigment which gives colour to the eye.
What is the iris?
The iris is a pigmented muscular body with a hole in the centre that forms the pupil, through which light rays enter to focus on the retina.
What is the function of the pupil?
The pupil controls the amount of light entering the eye by constricting and relaxing.
What is the retina?
The retina is the inner coat composed of layers of nerve fibres and light sensitive structures known as rods and cones which receive information about light and colour for interpretation by the brain.
What is myopia?
Myopia is short-sightedness where the eyeball is too long from front to back, causing images to be in focus in front of the retina.
What is hypermetropia?
Hypermetropia is long-sightedness where the eyeball is too long from top to bottom, causing images to be in focus behind the retina.
What is diplopia?
Diplopia is double vision.
What is hemianopia?
Hemianopia is partial blindness, the ability to only see half of the field of vision.
