Regular eye exams are an important way of monitoring the health of your eyes. An essential component of any thorough eye exam is a pupil dilation test.

Pupil dilation tests are not uncomfortable, but some patients consider them a nuisance because the visual effects of the eye drops used to dilate the pupils last for several hours. However, dilation testing is a critical part of an eye exam because it gives eye doctors a clear view of the retina, optic nerve, and blood vessels in the back of the eye.

What is a pupil dilation test?

A pupil dilation test is an eye exam that is used to evaluate the health of the retina and the light-sensitive tissue at the back of the eye. The only way to get a clear view of the back of the eye is to dilate (enlarge) the pupils. This allows more light to enter the eye without pupils constricting. After pupils have been dilated, the doctor is able to see a much greater area at the back of the eye.

Reasons for administering pupil dilation tests

Eye dilation is incorporated into routine eye exams because it gives doctors the chance to detect eye diseases and conditions at their earliest stages. Pupil dilation allows physicians to see all the way to the back of your eye. This area of the eye includes the retina, the optic nerve, and many important blood vessels. Pupil dilation can reveal any problems with these parts of the eye and can also reveal evidence of general health issues.

Here are just a few of the diseases and conditions that can be diagnosed with the help of pupil dilation: 

• Hypertension
• Diabetes
• Glaucoma
• Macular degeneration
• Retinal detachment
• Cataracts
• Infectious diseases
• Vasculitis

Performing pupil dilation tests

To begin the test, the doctor will place dilating drops in your eye. The drops take about 20-30 minutes to take effect. When pupils are completely dilated, the doctor will shine a light in your eye. Normally the pupil would contract, but the drops force the pupil to stay open and allow more light to pass through to the retina.

During a pupil dilation test, doctors examine the optic nerve, retina, and the blood vessels in the back of your eye. Changes to the optic nerve, retina, and blood vessels from one visit to the next can be a sign of eye disease. Pupil dilation tests can also help doctors recognize early signs of other health conditions, including hypertension, diabetes, and high cholesterol.

If you are having trouble with your vision, be sure to schedule a comprehensive eye exam with an optometrist.