Cataract is one of the leading causes of blindness in the United States. Approximately 24.5 million Americans have the lens-clouding eye condition, and the incidence is set to grow by 50 percent by 2020. As part of its efforts to support Cataract Awareness Month this June, the American Academy of Ophthalmology - the world's largest association of eye physicians and surgeons - is sharing with the public hundreds of commonly-asked questions and answers about the condition, which affects more than half of all Americans by age 80.

If not treated through a change in eyeglass prescription or surgery, cataracts can increase risk of permanent blindness. In addition, the longer advanced cataracts are left untreated, the more difficult it can be to successfully remove the cataract and restore vision. To help people understand the condition, its causes and treatments, Academy member ophthalmologists - medical doctors specializing in the diagnosis, medical and surgical treatment of eye diseases and conditions - have responded to hundreds of queries about cataracts submitted by the public through the Ask an Eye M.D. portal on GetEyeSmart.org. The following five questions and answers about cataracts are a small sampling of what is available for public reference on the website:

Can you have 20/20 vision and still be diagnosed with cataract?

"Yes, you can," answers Jeffrey Whitman, M.D. "Having a cataract just means that the lens of your eye has become cloudy and hardened - a process that begins at around 50 years of age and does not preclude 20/20 vision. It is only when it becomes visually significant - that is, when it degrades your vision, changes color perception, or causes glare at nighttime - that it requires surgical care."

How can I keep cataracts from getting worse?

"Most individuals over age 50 to 60 technically have age-related changes in their lenses that might be termed 'very early cataracts,'" says Charles P. Wilkinson, M.D. "In general, prevention is very difficult; but the most helpful practices include:

  • Avoid ultraviolet light from the sun with sunglasses
  • Avoid using steroid eye drops unless absolutely necessary
  • Avoid the rare medications that may be associated with cataract progression, including psoralens, a drug used along with light therapy to treat skin disorders; chlorpromazine, an antipsychotic; and some glaucoma medications."

Do cataracts cause eye pain?

"Cataracts do not cause pain except if they have been allowed to remain untreated for too long," explains Wayne Bizer, D.O. "In this case they cause a lot of pain and light sensitivity. Consult your ophthalmologist immediately if you are having eye pain."

Why do I need to stop wearing my contact lenses before cataract surgery?

"Before cataract surgery, important measurements of the surface of your eye must be taken," says W. Barry Lee, M.D. "Contact lenses alter the shape of the eye's surface, which can make the measurements inaccurate and lead to poor vision after the surgery. The length of time you must not wear contact lenses prior to your cataract surgery varies depending on the type of contact lenses you wear, so listen to your ophthalmologist's instructions carefully."

How long is recovery time after cataract surgery?

"Typically, this should only take several days," says Gary Hirshfield, M.D. "Of course, some issues may occur that require a longer recovery period, such as other eye conditions or rare surgery complications. Additionally, if both eyes need to be done and you are significantly near- or far-sighted, then there may be a period of time in between the surgery for each eye where the differences between the eyes may make your tasks difficult. Also, depending upon the surgical approach you may need a change in your eyeglass prescription which is usually done at about four weeks. However that can be accelerated to just several days provided you understand that the prescription may need to be revised in several weeks or months."

"While cataracts are one of the most common eye conditions - especially for older adults - when and why to seek treatment and what kind can be a complex decision," said Daniel J. Briceland, M.D., ophthalmologist and clinical spokesperson for the American Academy of Ophthalmology. "Some people wait too long before seeing a doctor about a suspected cataract, but they should really see an ophthalmologist for a comprehensive eye exam. Even if immediate treatment is not required, at least an ophthalmologist can confirm this and have a baseline from which to compare your vision if and when the cataract worsens later on."

Seniors who have not had an eye exam in the last three years and for whom cost is a concern may qualify for EyeCare America, a public service program of the Foundation of the American Academy of Ophthalmology, which provides eye exams and care at no out-of-pocket cost for eligible seniors age 65 and older through its network of more than 6,000 volunteer ophthalmologists. Visit www.eyecareamerica.org to see if you or your loved ones are eligible.

See all 250 cataract-related questions and answers or submit your own question at www.geteyesmart.org/ask.