Why Does An Optometrist Dilate Your Pupils?

When you go for an eye exam, it is sometimes important that your optometrist dilates your pupils. Pupil dilation is however determined by many factors such as your age, reason for your exam, and overall health and your risk of eye disease. It is not always necessary that once you go for an eye exam, your pupils will be dilated. 

During an eye dilation exam, doctors will use eye drops that are used for the purpose of widening your eyes.  Pupil dilation causes them to widen allowing more light and giving the optometrist a better view of the back of the eye. 

Undergoing a  dilated eye exam is particularly important as it allows the doctor to conduct a complete retina exam. This is quite important as many diseases and conditions in their earliest stages are detected through a dilated eye exam. Some of the conditions that your doctor can identify during an eye exam include:


Diabetic retinopathy is a diabetic eye disease that is most prevalent and a leading cause of vision. The condition can be detected through swelling and leaking blood vessel in the retina. It can also be identified through the abnormal growth of blood vessels in the retina.

Age-related Macular Degeneration

Age-related Macular degeneration (MAD) is a condition that mainly causes blindness in people who are over 50 years. Patients suffering from this condition will show yellow deposits or pigment clumps below the retina.  Age-related macular degeneration leads to deterioration of the macula which is responsible for sharp, central vision.


Glaucoma affects the optic nerve.  The optic nerve is responsible for relaying information to the brain from the eyes.  When patients of glaucoma go for a dilated eye exam, the result will show changes in the shape and color of the optic nerve fibers. The disease can also be identified through massive cupping of the optic disk. The optic serves as the entry point of the nerve fibers to the brain as well as their exit point from the eye.


Vasculitis refers to the inflammation of blood vessels.  There are several diseases that are. As a result oof blood vessel inflammation. The diseases are uncommon and can affect any blood vessel in the system. Vasculitis can cause damage to the affected organ and most specifically hinder the flow of blood to that organ.

Factors determining the need for Pupil Dilation

Eye dilation takes about 20 to 30 minutes for the eyedrops to start working. Once your eyes become dilated, you become more sensitive to light and focusing on the nearby objects becomes difficult. The effect can last up to several hours depending on the type of dilating eye drop used.  Whenever you feel that eye dilation is inconvenient, you can ask your doctor to arrange for another procedure. There are other options for eye dilation though they may not be as effective as having your eyes dilated to create a better view of the back of the eye.

Some factors that determine the necessity for eye dilation include:

Age: with an increase in age, the risk for eye disease also rises. It is recommended that individuals with age above 50 years go for a dilated eye exam.

Eye Health: if you have a history of eye disease that affects the back of the eye, like retinal detachment, may pose a threat to your future eye problems hence the need for a dilated eye exam.

Overall Health: some disease like diabetes may increase the risk of future eye problems.

The reason you are seeking an eye exam:  there are certain symptoms that will necessitate a dilated eye exam to identify their cause. Other conditions may not need dilation at every visit unless there are new symptoms.