Being a good pupil: What to expect when your eyes are dilated

Eyes are often described as the windows to our health, and like many windows, the wider they are open, the greater the opportunities for light and discovery.

This is why dilation exams are so essential for good eye health. A straightforward procedure, your doctor uses drops to widen your pupils, allowing in more light so your doctor can get a better look at the back of your eyes.1

Many people equate eye dilation with sunglasses, which patients are often required to wear afterwards. This is true, but what is not true—although it’s commonly believed—is that we need to have our eyes dilated at every eye exam. The need for the procedure really depends on the reason you’re visiting your eye doctor, your age and your overall health.

However, there are significant benefits to eye dilation and good reasons that it’s a standard practice among eye doctors when giving vision tests. Let’s explore when and why you should have your eyes dilated, what to expect and the benefits.

Why should you have your eyes dilated?

Like pulling aside the curtains to widen your view, dilation enlarges the pupil so more light enters the eye, providing an internal perspective few other procedures can produce. This enables the doctor to better inspect the important tissues at the back of the eye, including the retina, macula and optic nerve.2 Dilation is among the most effective ways to accurately diagnose certain diseases, including glaucoma, macular degeneration, diabetes and high blood pressure, as well as retinal detachment.3

Who should have their eyes dilated, and when?

Typically, you don’t need to have your eyes dilated if you’re only having a vision test to update a prescription. At age 60, however, dilated eye exams are generally recommended on an annual basis, unless you’re African-American. People with African heritage should begin at age 40 due to higher risks of glaucoma.4 Also, those who have diabetes are strongly recommended to have an eye dilation procedure at least once a year.5

What you should expect

A comprehensive eye exam that includes dilation can take 1 to 2 hours. During the procedure, your eye doctor will use a light and lens to look into the eye for signs of vision problems and eye diseases, many of which have no early warning signs.

After the dilation, your doctor will perform three tests:

Tonometry: To detect glaucoma, this procedure directs a quick puff of air onto the eye or gently applies a pressure-sensitive tip near or against the eye. Numbing drops may be applied first.

Visual field test: Another test to identify signs of glaucoma, this step measures your side or peripheral vision.

Visual acuity: This is the eye chart test, which allows your eye doctor to gauge how well you see at various distances.6

After the dilation exam, your pupils may remain enlarged for several hours, making it difficult to drive, work or read. Because your pupils are letting in a lot of light, your vision will be blurry and sensitive, so plan for alternative transportation—and bring sunglasses.7

1. “Is it necessary to have my eyes dilated during every eye exam?” Mayo Clinic,
2. “What is a comprehensive dilated eye exam?” National Eye Institute,
3. “Is it necessary to have my eyes dilated during every eye exam?” Mayo Clinic,
4. “What is a comprehensive dilated eye exam?” National Eye Institute,
5. “Facts about Diabetic Eye Disease,” National Eye Institute,
6. Ibid.
7. “What to expect when your eyes are dilated,” eyeSmart,