• Comprehensive eye examinations can detect signs of diease such as glaucoma.eyesight image by JASON WINTER from Fotolia.com
  
  When scheduling an appointment for an eye exam with an optometrist or ophthalmologist, you may wonder what to expect during your visit. Eye doctors use a wide variety of procedures to test the health of your eyes and vision. These range from having patients read off an eye chart to doctors' using a high-powered lens to examine the tiny structures inside the eye. A comprehensive eye exam can take roughly one hour or more, depending on the examiner and the number and type of procedures to be done.
  
  

Visual Acuity Test

• A visual acuity test examines the sharpness of your vision. The patient is seated facing a standard eye chart projected on a wall and is asked to read lines off of it, using one eye at a time. This tests the sharpness of near, and distance, sight.
  
  

Color Blindness Test

• These tests check the patient for color blindness and for hereditary vision deficiencies regarding the ability to distinguish colors. The most common way color blindness is tested is with the Ishihara plates test. This method uses plates of colored bubbles, and within the bubbles is a formed number of different colors of bubbles. People with color vision deficiencies will not be able to distinguish the number.
  
  

Cover Test

• The cover test checks how the patient's eyes function together. The eyes are covered alternately, while the patient stares at a distant object in the room, allowing for the examination of the eyes' alignment.
  
  

Refraction Test

• The refraction test allows the examiner to exactly determine eyeglass prescriptions. While looking at a line chart, the eye doctor places a series of lenses in front of the patient's eyes (each eye is examined separately) and asks the patient to choose which from a set of two lenses allows them to view the chart more clearly.
  
  

Slit-Lamp Test

• This test uses a slit-lamp instrument to check the health of the patient's eyes. This instrument gives the eye doctor a view of the inside structures of the eye, and thus, a look at any signs of infection or disease.
  
  

Pupil Dilation

• Pupil dilation provides a better look at the structures inside the eye because it enlarges the eyes' pupils. This is done by putting in eye drops, which take roughly 20 minutes to take effect. Because the pupils are enlarged, the patient will be sensitive to light and have difficulty focusing on close-up objects until the drops wear off.