How to Dilate or Shrink Your Pupils on Command

Last Updated: September 19, 2022 References

What's the secret to giving someone the "evil eye" or "bedroom eyes"? It's all in the size of your pupils, believe it or not. Scientists have actually studied how the way we feel about the things we see affects the size of our pupils (welcome to the world of pupillometry). So whether you want to stare down an enemy or make someone fall in love with you, this article is for you!

Method 1

Method 1 of 3:

Quick Dilation Techniques

1
Imagine a dark room. Research in 2014 showed that people can sometimes dilate their pupils by imagining dark shapes or dark scenes.^{[1]
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Research source} Think of those black bears assaulting a black campground at midnight, and your eyes may widen temporarily.
2
Focus on distant objects, or unfocus your eyes. Your pupils will get bigger as your eyes adjust to a further viewing distance.^{[2]
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Research source} Another way to approach this is to suddenly unfocus your eyes, blurring your vision as much as you can. If you're doing this correctly, your eyes will feel very relaxed; if you start to see double, you've probably crossed your eyes and need to start over.
- With these techniques, you won't be able to observe your own eyes, so you'll need to record yourself or have a friend watch.
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3
Face a darker part of the room. As you probably know, pupils grow to let in more light. If you aren't able to dim the surrounding lighting, you can still dilate your pupils by turning to face away from windows and light source.
4
Try tensing your stomach. Suck your stomach in and keep the muscles tight as you watch yourself in a mirror, to see whether your pupils increase. Some people can dilate their pupils in this way, although the underlying mechanism is unidentified. If you see no change after repeated tensing and bending, move on to a different technique.
5
Picture something that gives you an adrenaline rush. Your pupils can dilate dramatically when you are excited, or especially when sexually stimulated, due to the release of oxytocin and adrenaline. In addition to dilated pupils, these chemicals also causes your mind to race, muscles to tense up, and breathing to go faster. Through biofeedback, people can learn to "drive" their adrenaline levels up or down.^{[3]
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Research source}

Method 2

Method 2 of 3:

Powerful Dilation Techniques

1
Use allergy eye drops. Pick up some over-the-counter eye drops intended to be used to treat allergies. These can cause your eyes to become dilated. Be sure to read the instructions, and never use more drops than the label recommends.
2
Drink an espresso or take decongestants. Stimulants that work on the sympathetic nervous system can trigger your iris muscles to dilate your pupils. These include caffeine, ephedrine, pseudoephedrine, and phenylephrine. The last three are found in most over-the-counter decongestants.
3
Consider 5-HTP supplements. This is an over-the-counter drug you can find at pharmacies or anywhere that sells health supplements. While 5-HTP is generally safe, too high a dosage can cause dangerous effects from "serotonin syndrome."^{[4]
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Research source} Stick within the recommended dosage, and avoid 5-HTP entirely if you are on LSD, cocaine, antidepressants, large B-vitamin doses, or other substances that increase serotonin levels.^{[5]
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Research source}
4
Avoid other substances unless recommended by a doctor. Some prescription eye drops can dilate pupils, but have serious side effects that should be weighed by a doctor. If you are going through methadone treatment or have a medical condition that constricts your pupils, ask your doctor for advice on how to counteract this.
- Some recreational drugs cause dilated pupils as well. These are illegal in most areas, and can come with additional health risks if combined with other substances that cause dilated or constricted pupils.

Method 3

Method 3 of 3:

Constricting Your Pupils

1
Look at a bright, natural light. Stare at a bright window for a couple seconds. This will cause your pupils to shrink immediately. If you're outside, step into a patch of sunlight, rather than staying in the shadows.
- While light bulbs will work as well, natural light is more effective.
- Never look directly at the sun, as this could damage your eyes.
2
Focus intently on something close to you. Your pupils will narrow as you change your focus to something in front of your face. You can start by closing one eye and placing your finger in front of the open one. With practice, you can learn to focus your eyes close even when there's nothing there.
3
Consider medication. There are a variety of medications used to constrict the pupil, but these are usually only available as a prescription, or even administered by the doctor only.
- Opiates constrict pupils, but most examples are illegal in most countries. They can also cause serious harm, especially when combined with other drugs that cause pupil constriction or dilation.

Community Q&A

Question

How does the pupil dilate and constrict?

wikiHow Staff Editor
Staff Answer
This answer was written by one of our trained team of researchers who validated it for accuracy and comprehensiveness.

wikiHow Staff Editor

Staff Answer

There are two sheets of circular muscles in the iris, one that expands to dilate the pupil in low light and one that contracts to constrict it in bright light.
Question

What can make your pupils big?

wikiHow Staff Editor
Staff Answer
This answer was written by one of our trained team of researchers who validated it for accuracy and comprehensiveness.

wikiHow Staff Editor

Staff Answer

The most common reason is that the lighting is dark or dimly lit, but there are other reasons why your pupils might dilate. There are certain prescription drugs, such as atropine, antihistamines, decongestants, tricyclic antidepressants, botox, and certain anti-seizure drugs that can cause this. Many illegal drugs are also known to cause dilated pupils, including, cocaine, amphetamines, psychedelics and ecstasy. Sometimes a head injury, a stroke or another brain disorder can cause pupils to dilate as well as certain injuries to the eye itself. Sometimes pupils can dilate for no specific reason, even for several days, but not be dangerous or indicate a more serious condition (known as benign episodic unilateral mydriasis).
Question

I am newly taking Naltrexone, and it has made my pupils big. The people around me think I am on drugs. What can I do?

Community Answer

Explain to them that you are on a medicine that has that side effect.

Warnings

Dilating and constricting your pupils with conscious effort can cause eye strain. Stop the attempts for a day or two if your eye muscles feel sore or twitch.

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Your pupil shrinks in bright light to avoid overstimulating your nerves. Don't dilate your pupils on a sunny day; if someone takes a flash photo of you or turns on bright lights, you could damage your eyesight.

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Avoid over-the-counter medications that contain belladonna extract or atropine. These are dangerous drugs that should only be administered by a doctor.^{[6]
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