(HealthDay News) -- Early diagnosis and treatment can control glaucoma before vision loss or blindness occurs.

Everyone should be tested for glaucoma at least every two years. If you are over 65, having a glaucoma test once a year could help prevent permanent damage to your vision.

If you are among the 3 million Americans who has glaucoma, the American Health Assistance Foundation offers these suggestions on living with the disease:

• Follow your doctor's instructions closely and take your medications as prescribed.
• Whenever you see a new doctor or health-care professional, make sure they know you have glaucoma.
• Carry an identification card in your wallet that lists your medicines and treatment schedule.
• Always keep an extra supply of medicine on hand for emergencies.
• If you have any problems with your medicine, talk to your doctor as soon as possible.