How Long Does Pupil Dilation Last? | Blog

What Does It Mean to Dilate Your Pupils?

Having dilated pupils means the size of your pupils (the little black dots in the center of your eyes) is larger than normal. Pupil dilation is a natural response that the eyes have to low-light environments. However, an eye doctor will sometimes force the pupils to dilate so they can perform specific exams or procedures.

An infographic showing examples of dilated and non-dilated pupils

How Pupil Dilation Works

The role of the pupil is to adjust in size to allow the correct amount of light into the eye. For a clear image to result, there must be a precise amount of light that focuses through to the back of the eye and onto the retina. Too much light can cause a glare and too little light can make objects hard to recognize.

With help from muscles in the iris (the colored part of your eye), the pupil constricts, or gets smaller, in bright conditions to limit how much light enters your eye. The pupil dilates, or gets bigger, in dim conditions to let in more light so it’s easier for you to see.

It’s also normal for your pupil to get smaller when you focus on something up close.

When an eye doctor dilates your pupils for an eye exam, they do so using special dilating eye drops. The two types used most often are mydriatic and cycloplegic eye drops.

These eye drops work by stimulating a muscle called the iris dilator, which is responsible for widening the pupils. They also inhibit the iris sphincter, which is the muscle that constricts the pupils. So, not only are the pupils dilated, but they won’t constrict in response to bright light like they normally do.

It takes around 20–30 minutes after the drops are applied to start working. The pupils should be widened significantly once they take full effect.

Why Would You Have Your Pupils Dilated?

The pupil is, quite literally, the window to the eye. Eye doctors can look through the pupil and see structures at the back of your eye, including the retina and optic nerve.

While an eye doctor can still conduct a comprehensive eye exam without dilating the pupils, it limits how well they can see the other parts within the eye. Having dilated pupils makes it possible to fully examine the internal structures of your eyes.

Importance of Dilated Eye Exams

Having a comprehensive eye exam with dilated pupils is important because it gives your optometrist a better look at what’s going on in your eyes. This is especially valuable in diagnosing certain eye problems, including:

Diabetic retinopathy
Macular degeneration
Glaucoma
Retinal detachment or tear
Ocular tumor

A dilated eye exam also makes it possible for an optometrist to fully view a cataract, which is cloudiness in the lens of the eye.

How Long Does Eye Dilation Last?

On average, dilated pupils last around 3–6 hours, but dilation can certainly take longer depending on your circumstances. It depends on the type of eye drops your doctor uses, your eye color, and your age.

It’s common for an optometrist to use a stronger solution on children’s eyes, which often means it takes longer for their pupils to return to normal size.

Lighter-colored eyes, like blue, green, and hazel, typically respond more quickly to dilating solutions and stay dilated longer. Brown eyes take longer to dilate and have a shorter duration period.

Eye Dilation Side Effects

When dilation eye drops are first applied, you may feel some stinging in your eyes. Some eye doctors will apply a numbing agent first to alleviate the stinging sensation of the dilation drops.

The most common side effects of having your pupils dilated include:

Light sensitivity
Blurred vision
Difficulty focusing, especially on close-up objects

To manage these side effects, you should avoid near work (like reading) and wear sunglasses to help with any light sensitivity.

Though rare, it’s possible to have an allergic reaction to dilation eye drops. Signs of this include:

Flushing of the face
Increased pulse
Fever
Dry mouth
High blood pressure
Drowsiness
Constipation

If you experience any kind of unexpected reaction or side effects, let your doctor know so they can assess and monitor your situation.

What Not to Do After Eye Dilation

Since your pupils will probably still be dilated immediately after your eye exam, it’s important to know what activities to avoid so you can plan around it. Here are some of the main things you should avoid when your pupils are dilated:

Driving – The blurred vision you experience with pupil dilation makes it unsafe to drive after your eye exam. If the sun’s out, it could be even worse. It’s best to make arrangements for someone else to drive while your eyes are dilated.
Screen use – Bright light from the sun or a screen can be irritating with dilated pupils. Plus, focusing on a smartphone or tablet can be difficult.
Eye rubbing – Eye rubbing isn’t particularly good for your eyes anyway, but it can be especially harmful when your pupils are dilated. Try to close and rest your eyes until your pupils return to normal, and apply artificial tears if your eyes feel itchy.
Near work – Near work is challenging because it’s hard for your eyes to focus up close while you have dilated pupils. If you try to “fight through the dilation,” it can lead to eye strain. It’s best to just wait until your eyes are back to normal.
Machinery use – Do not try to use kitchen appliances, power tools, or workout equipment while you have dilated pupils. With your vision compromised, you are not able to operate them safely.

If you’re worried that eye dilation may conflict with an important event, discuss your concerns with your eye doctor before you schedule an exam.

How to Make Eye Dilation Go Away Faster

There aren’t many ways to speed up the process of getting your pupils back to normal. In the past, optometrists would apply Rev-Eyes (dapiprozole) — a medication that could reverse dilation in as little as 1–2 hours. However, it’s rarely used these days because of the medication’s cost and side effects.

When to See an Eye Doctor

Eye dilation that lasts for days rather than hours could be due to a complication of dilation drops called cycloplegia. This is a temporary condition in which the focusing muscles of the eye become paralyzed. While bothersome, the condition typically resolves on its own over a period of time.

If you notice your pupils stay dilated without the use of dilation eye drops, make an appointment with your eye doctor. You should also seek medical attention if one of your pupils is significantly more dilated than the other. This could indicate a serious problem and should be examined by an eye care professional.

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