Safety measures may be necessary if you have any vision problems. For example, if you have trouble seeing at night, you should not drive after dusk. It may be helpful to increase the amount of light in a room or arrange a home to remove hazards. A specialist at a low-vision clinic may be able to help.

Call 911 if:

• You experience partial or complete blindness in one or both eyes, even if it is only temporary.
• You experience double vision, even if it is temporary.
• You have a sensation of a shade being pulled over your eyes or a curtain being drawn from the side.
• Blind spots, halos around lights, or areas of distorted vision appear suddenly.
• You have eye pain, especially if also red. A red, painful eye is a medical emergency.

Call your provider if you have:

• Trouble seeing objects to either side
• Difficulty seeing at night or when reading
• Gradual loss of the sharpness of your vision
• Difficulty distinguishing colors
• Blurred vision when trying to view objects near or far
• Diabetes or family history of diabetes
• Eye itching or discharge
• Vision changes that seem related to medication (Do NOT stop or change a medication without talking to your doctor.)

Your provider will check vision, eye movements, pupils, the back of your eye (called the retina), and eye pressure when needed. An overall medical evaluation will be done if necessary.

Your provider will ask questions about your vision problems, such as:

• When did this begin? Did it occur suddenly or gradually?
• How often does it occur? How long does it last?
• When does it occur? Evening? Morning?
• Is the problem in one eye or both eyes?
• Is your vision blurred, or is there double vision?
• Do you have blind spots?
• Are there areas that look black and missing?
• Is side (peripheral) vision missing?
• Are halos (circles of light) seen around shiny objects or lights?
• Do you see flashing lights or zigzag lines?
• Do you have sensitivity to light?
• Do stationary objects seem to be moving?
• Are colors missing? Is it difficult to differentiate colors?
• Is there pain?
• Are your eyes crossed? Does one or both of your eyes "drift"?
• Have you had an injury, infection, allergy symptoms, added stress or anxiety, feelings of depression, fatigue, or headache in the last few weeks to months? Have you been exposed to pollens, wind, sunlight, or chemicals in this time frame? Have you used any new soaps, lotions, or cosmetics?
• Is your vision better after you rest?
• Is it better with corrective lenses?
• Are there other symptoms present like redness, swelling, headache, pain, itching, discharge/drainage, a sense that something is in the eye, increased or decreased tearing, etc.?
• What medications do you take?
• Do you have diabetes, or is there a family history of diabetes?

The following tests may be performed:

• Slit-lamp examination
• Refraction test
• Tonometry

Treatments depend on the cause. Surgery will be recommended for some conditions (such as cataracts). Diabetics must control their blood-sugar level.