Exams and Tests

To detect a cataract, the eye-care provider examines your lens. A comprehensive eye examination usually includes the following:

• Visual acuity test: An eye chart test is used to measure your reading and distance vision.
  
  
• Refraction: Your eye doctor should determine if glasses would improve your vision.
  
  
• Glare testing: Vision may be significantly altered in certain lighting conditions and normal in others; in these circumstances, your doctor may check your glare symptoms with a variety of different potential lighting sources.
  
  
• Potential acuity testing: This helps the ophthalmologist get an idea of what your vision would be like after removal of the cataract. Think of this as the eye's vision potential if the cataract was not present.
  
  
• Contrast sensitivity testing: This checks for your ability to differentiate different shades of gray, which is often this limited by cataracts.
  
  
• Tonometry: a standard test to measure fluid pressure inside the eye (Increased pressure may be a sign of glaucoma.)
  
  
• Pupil dilation: The pupil is enlarged with eye drops so that the ophthalmologist can further examine the lens and retina. This is important to determine if there are other conditions which may ultimately limit your vision besides cataracts.