Sagital Flashcards
The eyeball has an AP diameter of
24 mm
The eyeball is a (Blank) and (Blank) which houses the structures responsible for (Blank) It lies in a bony cavity within the facial skeleton – known as the (Blank )
BILATERAL AND SPHERICAL ORGAN
VISION
BONY ORBIT
How the Eye Works?
In a number of ways, the human eye works much like a digital camera:
Light is focused primarily by the (Blank)— the clear front surface of the eye, which acts like a camera lens.
Cornea
The (Blank) of the eye functions like the diaphragm of a camera, controlling the amount of light reaching the back of the eye by automatically adjusting the size of the pupil (aperture).
Iris
The eye’s (Blank) is located directly behind the pupil and further focuses light. Through a process called accommodation, this lens helps the eye automatically focus on near and approaching objects, like an autofocus camera lens.
Crystalline Lens
Light focused by the cornea and crystalline lens (and limited by the iris and pupil) then reaches the (blank)— the light-sensitive inner lining of the back of the eye. The (blank) acts like an electronic image sensor of a digital camera, converting optical images into electronic signals. The optic nerve then transmits these signals to the visual cortex — the part of the brain that controls our sense of sight.
Retina
The cornea is the transparent and clear front surface of the eye. It lies directly in front of the iris and pupil, and it allows light to enter the eye.
The cornea provides approximately 65 to 75 percent of the focusing power of the eye.
The remainder of the focusing power of the eye is provided by the crystalline lens, located directly behind the pupil.
The function of the cornea is to allows for the passage of light into the eye and it also focuses the light.
Cornea
It gives color to the eye. The (BLANK ) of the eye is the thin, circular structure made of connective tissue and muscle that surrounds the pupil.
In addition to giving the eye its color, the (Blank) acts like the diaphragm of a camera and controls the size of the pupil. One muscle within the (blank) constricts the pupil in bright light (full sunlight, for example), and another (blank) muscle dilates (enlarges) the pupil in dim lighting and in the dark.
IRIS
The (blank) is the opening in the center of the iris . The function of the pupil is to regulate the amount of light entering the eye.
PUPIL
The crystalline lens is a unique transparent, biconvex, avascular intraocular structure with slightly more curved posterior surface .The radius of curvature of anterior surface is 10 mm and that of posterior surface is 6 mm.
The crystalline lens is responsible for accommodation. It is located behind the iris and in front of the vitreous body.
CRYSTALLINE LENS
The (blank) is the clear, thin membrane that covers part of the front surface of the eye and the inner surface of the eyelids.
CONJUNCTIVA
A tough white skin (made of tissue) that covers all of the eyeball except the cornea.
Sclera
The choroid is the middle layer of tissue in the wall of the eye. It can be found between the sclera and the retina.
This thin layer of tissue is made up almost entirely of blood vessels. These blood vessels supply oxygen and nutrients to the outer part of the retina. In short, the choroid is the life source that keeps the retina healthy and functioning
CHOROID
The retina is the sensory membrane that lines the inner surface of the back of the eyeball. It’s composed of several layers, including one that contains specialized cells called photoreceptors.
Functions of the Retina
Converts light waves to electrical signals
The part of the eye where the image falls and then the brain will interpret.
RETINA
