Anatomy of the Eye

Cornea - the clear front part of the eye

Iris - the colored part of the eye behind the cornea

Pupil - the round opening in the iris which lets the light into the eye

Lens - the clear lens behind the iris which focuses the light entering the eye on the retina so we can see clearly

Retina - the nerve layer at the back inside of the eyeball where the light is focused and which transfers the light into nerve signals to be sent to the brain where vision takes place.

Macula - the part of the retina where the nerve receptors are most dense, corresponding to the clearest possible central vision

Optic Nerve - carries the vision signals from the retina to the visual cortex of the brain where sight or vision occurs

Contact Lenses - are a form of vision correction made of materials that float on the layer of tears on the surface of the cornea and change the angle of the light entering the eye.

Nearsightedness (Myopia) - Close objects are seen clearly, objects at a distance are blurry

Farsightedness (Hyperopia) - Far away objects are seen clearly, blurriness or strain are experienced trying to focus at near distances.

Astigmatism - Objects appear blurry or distorted at all distances because of the irregular shape of the cornea (front part of the eye)

Presbyopia - Part of the aging process, this involves increasing difficulty focusing for near vision such as reading, generally begins about age 40.

Glaucoma - A disease condition of the eye involving increased internal eye pressure which damages the retina and optic nerve. Glaucoma can cause vision loss and even blindness if not treated.

Cataracts - A gradual clouding of the clear lens of the eye which causes blurred or hazy vision. Left untreated it can lead to blindness.

Macular Degeneration - A deterioration of the retina which causes loss of clear central vision

Binocular Vision - involves both eyes working as a team to form a single clear picture. Binocularity is essential for good depth perception.

Strabismus - refers to "crossed" eyes, or a turned eye which does not work with the other eye but remains turned inward, outward, up, or down.

Amblyopia - commonly called "lazy eye" is a condition where one of the eyes does all the focusing work and the other eye does little or none, resulting in a loss of binocular vision.

20/20 - a standard of good distance vision which involves reading letters of "size 20" from 20 feet away