Most of the focusing power in the eye occurs along the front surface, called the cornea, which is the clear "window" in the front of the eyeball. The next structure involved in focussing is the lens, which sits behind the cornea inside the eye. The ideal cornea has a round, symmetrically curved surface, like a basketball. Astigmatism is caused by an "out of round" cornea or a lens that is not symmetrical. As a result, people with significant astigmatism may have distorted or blurry vision.
Amblyopia: Also known as "lazy eye," amblyopia is a condition that starts in childhood in which vision has not developed properly in one eye or the other. If amblyopia is left untreated, a child's vision will not develop correctly, and as the brain matures, one eye will remain with poor vision.
Aqueous humor: The clear, watery fluid between the lens and the cornea.
Astigmatism: A condition in which blurred vision is caused by the cornea being shaped more like a football than spherical like a basketball. Astigmatism may be compensated for through eyeglasses or contacts, or it can be corrected through refractive surgery.
Beta-blocker: A medication used in the treatment of glaucoma, beta-blocker eye drops help reduce the pressure within the eye by reducing the production of aqueous humor.
Carbonic anhydrase inhibitor: A type of medication used to treat glaucoma. Carbonic anhydrase inhibitors work by reducing the production of aqueous humor, thereby reducing pressure inside the eye.
Choroid: The layer of blood vessels between the retina and the sclera.
Choroiditis: A form of uveitis that causes an inflammation of the layer beneath the retina.
Conjunctiva: A thin layer of tissue that lines the inside of the eyelids as well as the outer surfaces of the sclera.