Types of Vision Testing - Information for Eye Care Patients

There are many types of vision tests that have been developed to determined many aspects of this sense. They also aid eye specialists in determining the extent of various eye conditions and diseases that may exist in patients and help them determine the best course of treatment. Below is information on the most common vision tests and why they are a necessary part of periodic eye examinations.

The first type is the visual field test. This type of exam requires a person to stare at a light in the center of his or her vision. Lights are then shown in the periphery and is used to determine how far the person can see on each side without any head movement. This is known as the perimetry test and measures peripheral vision. It is often used to detect the onset of open-angle glaucoma, an eye disease that can potentially blind a patient if treatment is not sought.

Another common exam is the cover test. Here, the patient’s eyes are alternately covered and he or she is asked to focus on a distant object. Eye specialists use this exam to look at the eye movement that occurs when the object is being viewed. This can aid doctors in diagnosing poor depth perception and other conditions.

Tonometry is another common eye test. It is used to measure eye pressure and is very useful for patients who are candidates for or already have open or narrow angle glaucoma. These patients will need to have this test performed at least once a year, usually more often if glaucoma is present, and make sure they are faithful about keeping appointments. The eye pressure test is also performed on patients who need glasses and is usually not as critical, but is still a normal part of the eye examination.

All of the tests mentioned above may be performed in the course of one eye examination. The eye pressure test may be performed in the morning at one appointment and in the afternoon for the next. This is because the reading may vary from one time of the day to another and physicians find it helpful to understand this variation.