Itchy, red, swollen, tearing eyes often mean eye allergies.
Amblyopia (Lazy Eye)
Amblyopia usually develops in young children and can mean permanent visual dysfunction if not diagnosed and treated early in life.
Optical defect in which refractive power is not uniform in all directions. A form of distorted vision which is usually correctable with eyeglasses, contact lenses or refractive surgery.
Inflammation of the eyelids can cause chronic eye irritation, tearing, foreign body sensation and crusty debris.
Cataracts and Cataract Surgery
Opacity or cloudiness of the crystalline lens (cloudy vision), which may prevent a clear image from forming on the retina. Surgical removal of lens may be necessary if visual loss becomes significant, with lost optical power replaced with an intraocular lens, contact lens or glasses (fortunately cataract removal is a routine procedure). May be congenital or caused by trauma, disease, or age.
Learn about the different types of color deficiency and how to cope in a color-coded world. Color vision deficiency affecting red-green discrimination.
Conjunctivitis (Pink Eye)
Inflammation of the conjunctiva (mucus membrane that covers the white of the eye and inner eye lid surfaces). Usually characterized by discharge, grittiness, redness and swelling.
Diabetes causes retinal degradation that can be sight-threatening.
Dry Eye Syndrome
Corneal conjunctival dryness due to deficient tear production. Can cause foreign body sensation or burning eyes.
Ocular herpes is a recurrent viral infection that can sometimes lead to serious vision loss.
Floaters and Spots
Particles that float in the vitreous and cut shadows on the retina; seen as spots, cobwebs, spiders, etc. They're usually harmless, but they can also be signs of a serious problem, such as a detached retina.
A damaged optic nerve and a diminishing field of vision result from glaucoma.
If you're hyperopic, you may see better from a distance than up close, or your vision may be blurred at all distances.
Special contact lenses can help people with thinning, bulging corneas to see better.
Macular Degeneration (AMD)
Group of conditions that include deterioration of the macula, resulting in a loss of sharp central vision. An estimated 13 million Americans have signs of this sight-threatening disease, the world's number one cause of blindness.
Focusing defect in which the eye is over powered.
About a third of the population can see fine up close, but distant objects are a blur.
Elevated eye pressure has no symptoms, but it is easily detected in an eye exam. Take care of it before it develops into glaucoma.
Usually a severe headache often one-sided and accompanied by nausea. May be preceded by an aura of lightning flashes or expanding circles of light.
Photophobia (Light Sensitivity)
Lots of eye conditions can be the underlying cause of bothersome light sensitivity.
Pinguecula and Pterygium
Pingueculae are yellowish, slightly raised lesions that form on the surface tissue of the white part of your eye (sclera) close to the edge of the cornea. They are typically found in the open space between your eyelids (palpebral fissure), which also happens to be the area exposed to the sun. While pingueculae are more common in middle-aged or older people who spend significant amounts of time in the sun, they can also be found in younger people and even children - especially those who spend a lot of time in the sun without protection such as sunglasses or hats.
Greek for "elder eye," presbyopia means difficulty see close up for those in their 40s and older.
Pterygia are wedge- or wing-shaped growths of benign fibrous tissue with blood vessels (fibrovascular), typically located on the surface tissue of the sclera. In extreme cases, pterygia may grow onto the eye's cornea and interfere with vision. Because a pterygium resembles tissue or film growing over the eye, a person who has one may become concerned about personal appearance. As with pingueculea, prolonged exposure to ultraviolet light from the sun may play a role in the formation of pterygia.
Flashes of lights and floating spots are classic warning signs of a detached retina, so get this checked out right away.
Misaligned eyes can mean not only crossed eyes but also eyes that point outward, upward or downward.
A stye (also spelled "sty") develops when a gland at the edge of the eyelid becomes infected. Resembling a pimple on the eyelid, a stye can grow on the inside or outside of the lid. Styes are not harmful to vision, and they can occur at any age.
-Stye Symptoms and Signs
A stye initially brings pain, redness, tenderness and swelling in the area, then a small pimple appears. Sometimes just the immediate area is swollen; other times the entire eyelid swells. You may notice frequent watering in the affected eye, a feeling like something is in the eye or increased light sensitivity.
Inflammation of the uvea can be painful and may cause light sensitivity, floaters, and blurred vision.
Information from http://www.allaboutvision.com/