Why Do Eye Doctors Dilate Your Eyes? What to Expect at Your Eye Exam

Why Do My Pupils Need to Be Dilated?

In an eye examination where dilation isn't performed, it can be challenging for your optometrist to gain a comprehensive view of your eye's complete anatomy. To examine both the external and internal parts of your eye, optometrists use a combination of bright light and a magnifying lens, looking through the pupil, the black circle in the middle of the eye that changes in size to allow light in and out.  

However, when exposed to bright light, the pupil naturally contracts, making it harder for the optometrist to get an unobstructed view using their light. Dilation of the pupil is essential as it keeps the pupil wide, allowing for a more thorough examination. 

Once the pupil is dilated, your optometrist can obtain a clearer view of the eye's interior and exterior structures. This allows for a detailed inspection of the back of the eye. This thorough exam is essential for early detection of eye diseases like diabetic retinopathy, age-related macular degeneration, and glaucoma. It also enables the doctor to identify any signs of other eye-related issues, including retinal detachments or tumors. 

Many eye conditions, particularly in their initial stages, may not present noticeable symptoms, making it vital for your doctor to examine the inside of your eye comprehensively. A dilated eye exam can also reveal ocular signs of systemic health conditions, helping in early detection and preventive care. 

How Are Eyes Dilated?

Eye dilation is a quick and painless process that your eye doctors complete. They will administer a local anesthetic before applying eye drops to each eye to keep the pupils wide during the exam. After the drops are administered, it takes approximately 15-30 minutes for your eyes to fully dilate. However, if you have light-colored eyes, it may occur faster, as they usually dilate faster than dark-colored eyes. 

How Long Does Pupil Dilation Last?

Pupil dilation typically lasts 1-2 hours, depending on the type of eye drops used. When you visit your eye doctor for a dilated eye exam, make sure to ask for a specific time frame.   

After your dilated eye exam, you may experience light sensitivity or blurred vision. These tips can help you effectively manage your warped vision after pupil dilation:  

• Bring sunglasses with you, or ask your doctor for a disposable pair, in case of light sensitivity after your exam. 

• If you wear contacts, bring your glasses along. Your doctor may not want you to put your contacts back in after the dilation. 

• Ask a friend or family member to drive you home from the appointment. 

Risk Factors That Require a Dilated Eye Exam

There are certain risk factors that require more frequent eye exams to ensure you can catch potential problems before they worsen. By completing regular dilated eye exams, your doctor can closely monitor changes in your eye health and provide preventative care. Depending on your existing risk factors, your doctor can provide recommendations on how often you should complete a dilated eye exam.  

You will likely need a dilated eye exam every one to two years if you: 

• Are over the age of 60 

• Have been diagnosed with diabetes or high blood pressure 

• Are of African American descent and over age 40 

• Have a family history of glaucoma