Diagnosis of CataractsEn Español (Spanish Version)
Although you might think you have a cataract, the only way to know for sure is to have an eye examination. To detect a cataract, an ophthalmologist or optometrist examines the lens and may do other tests to learn more about the structure and health of your eye. A comprehensive eye examination for cataracts usually includes:
- Visual Acuity Test—This eye chart test measures how well you see at various distances. This may include a test of your vision under conditions of low contrast and/or glare.
- Slit Lamp Exam—This is an examination of the eye using a specialized microscope that magnifies the eye.
- Tonometry—This is a standard test to measure fluid pressure inside the eye (increased pressure may be a sign of glaucoma).
- Dilated Eye Exam—The doctor gives you special eye drops to widen your pupil, which allows better examination of the lens and the structures of the back of the eye. This allows your doctor to examine the lens in more detail to detect a cataract.
Mayo Foundation for Medical Education and Research
website. Available at:
The Merck Manual of Medical Information.
17th ed. Simon and Schuster, Inc; 2000.
National Eye Institute website. Available at:
Last Reviewed [Under Medical Review]