context: Nearsightedness : Blurry vision that gets worse when you look at distant objects. Your doctor will call it myopia. You may have very good close vision. Farsightedness : Blurry vision when you look at close up objects. Near and far objects may both look fuzzy. The doctor will say you have hyperopia. Astigmatism : You might have blurry or double vision at any distance. You may also be nearsighted or farsighted. Detached retina : You'll notice a sudden onset of flashing lights often paired with black floaters in your vision. It won't hurt, but at first you might see a dark curtain or veil covering a portion of your vision. Cover one eye and then the other and compare the sight in each one. Color blindness : You have trouble with shades or intensity of colors. Because it's all about perception, you may not know there's a problem until the doctor finds it. This genetic condition mainly affects men. Night blindness : It's hard to see objects in dim light. Cataracts : Because they develop slowly, your first symptom may be trouble with the vision test for your driver's license renewal. Or your doctor could spot it during a routine eye exam. Symptoms include: Hazy vision that might be worse in bright light Weaker vision at night, particularly when driving; trouble seeing movement, details, or objects (especially street signs) Blinding or uncomfortable glare from automobile headlights or bright sunlight A need for brighter light for reading Colors look faded or yellow Double or triple vision (images overlap) in one eye only A normally dark pupil looks milky white or opaque (advanced cases) Painful inflammation and pressure within the eye (very advanced case) Strabismus: Your eyes don't move together as they should. Both eyes or just one could be crossed inward or outward. A child who has it may rub one or both eyes often. She could also squint, tilt her head, or close one eye to see things better. Glaucoma: Symptoms may depend on the type of glaucoma: Chronic open-angle glaucoma: No symptoms until it's caused serious eye damage. Acute glaucoma: A sudden onset of severe throbbing eye pain, headaches, blurred vision, rainbow halos around lights, red eyes, nausea, and vomiting. It's a medical emergency. Secondary glaucoma: This type results from an injury, inflammation, a drug, cataracts, or diabetes. Your symptoms will be tied to the cause. Congenital glaucoma: This type affects infants. You'll notice teary or cloudy eyes, unusual sensitivity to light, and enlarged corneas. It can affect one or both eyes. Macular degeneration : Dim or wavy vision, especially when you read. Straight lines often look crooked. Gradual, painless loss of precise central vision. Blank spots in your central field of vision. Call the doctor about vision problems if you: Have symptoms of retinal detachment such as floaters or flashes of light in your vision. You need immediate treatment to save vision in that eye. Feel like a dark curtain covers part of your side vision. Call right away to rule out other serious causes of this problem, like stroke. Become unusually sensitive to bright light. You may have inflammation inside your eye (iritis/uveitis). Have a foreign object in your eye that won't come out with water. If you don't treat it, you could scar your eye or get an infection. Have discomfort when you wear contacts or have pain that won't go away even after you take the contact out. You may have a scratch, inflamed cornea (the doctor will call this keratitis), or a corneal ulcer. Get an eye injury that affects your vision. You might have internal bleeding or a fracture of the bone around your eye. This is a medical emergency. A good rule of thumb: Go to the doctor if you have any unusual: Redness Irritation Pain Discharge Vision changes