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The Daily Insight

Can drugs cause unequal pupils

Author

Rachel Hunter

Published May 04, 2026

Accidental contamination of many drugs, such as cocaine may cause anisocoria. In addition to ocular side effects, cocaine use is associated with a number of complications, involving the cardiovascular, respiratory, neurological, and gastrointestinal systems.

What drugs cause uneven pupils?

Stimulants and psychotropic substances most commonly cause pupil dilation. However, this symptom can result from ingesting alcohol, mescaline, cocaine, ecstasy, LSD, psilocybin, MDMA, amphetamines, cannabis, inhalants, narcotics, hallucinogens, bath salts, ketamine, and SSRI antidepressants.

What do unequal pupils usually indicate?

If the larger pupil is abnormal, the difference between pupil sizes is greater in bright light. If the smaller pupil is abnormal, the difference is greater in the dark. Eye disorders that cause unequal pupils include birth defects and eye injury. Also, certain drugs that get into the eye may affect the pupil.

Can drugs make one pupil bigger than the other?

Medications That Affect the Pupils Some medications and illegal drugs can cause your pupils to change size in one or both eyes. Medications that can affect the way your pupils look include: Amphetamines.

Is anisocoria caused by drugs?

Small pupils may be caused by opiates, clonidine, organophosphates, pilocarpine, and prostaglandins. Generally, medications taken systemically will not cause anisocoria since both pupils will constrict or dilate but can cause anisocoria if the medication gets into only one eye.

What drugs cause dilated pupils?

The most common drugs that can cause dilated pupils are: cocaine, methamphetamine, LSD, and marijuana. Other drugs can cause your eyes to constrict (called miosis); the most common one with this effect is heroin. Alcohol, barbiturates, and heroin can cause diplopia, which is the scientific term for “seeing double.”

How long does it take for your pupils to go back to normal after drugs?

It depends on the mydriatic drug (drops to dilate the pupil) used. Typically, the drops used to perform a normal examination of the eye make the pupil dilate very quickly, in about 15 or 20 minutes, and the effect disappears in about an hour and a half.

How long does it take for pupils to UN dilate after drugs?

After your eyes are fully dilated, the effects will last for four to six hours for most people. Some people feel the effects of dilating drops for longer, including people with lighter color eyes. Dilation in children can last up to a full day after the exam.

What drugs make your pupils get bigger?

  • amphetamines.
  • bath salts.
  • benzodiazepines.
  • cocaine and crack cocaine.
  • crystal methamphetamine.
  • ecstasy.
  • ketamine.
  • LSD.
Why are my pupils different sizes all of a sudden?

If a person’s pupils are suddenly different sizes, it is best to seek medical attention. While not always harmful, a sudden change can indicate serious and dangerous medical conditions. It is especially important to seek medical attention if the change occurs after an injury or with other symptoms.

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Can anxiety cause uneven pupils?

Because elevated stress can adversely affect the nervous system and how the sensory organs function, stress, including anxiety-caused stress, and a lack of sleep can affect the size of the pupils in the eyes.

Will anisocoria go away?

Simple anisocoria This is a benign condition that causes the pupils to differ in size, usually by up to one millimeter in diameter, without affecting the pupils’ response to light. This condition can be intermittent or constant, and may even go away on its own without medical intervention.

Is anisocoria serious?

One pupil may be bigger than normal, or one pupil may be smaller than normal, resulting in unequal pupils. In most cases, anisocoria is mild, constant and no cause for concern. But if it occurs suddenly, this can be a sign of a serious medical condition and you should see an eye doctor immediately.

What drugs affect vision?

Certain classes of drugs are known to cause eye problems. These include diuretics (water pills), antihistamines, antidepressants, drugs that lower cholesterol, beta-blockers and birth control pills. “Antihistamines often cause a very significant dry-eye syndrome,” Andreoli says.

When your pupils dilate do they get bigger or smaller?

Your pupils get bigger or smaller, depending on the amount of light around you. In low light, your pupils open up, or dilate, to let in more light. When it’s bright, they get smaller, or constrict, to let in less light. Sometimes your pupils can dilate without any change in the light.

What does it mean when your pupils get smaller?

When you’re in bright light, it shrinks to protect your eye and keep light out. When your pupil shrinks (constricts), it’s called miosis. If your pupils stay small even in dim light, it can be a sign that things in your eye aren’t working the way they should.

Does Adderall dilate pupils?

Adderall mainly stimulates the sympathetic nervous system, which triggers the body’s “fight or flight” responses, such as pupil dilation, increased blood pressure and heart rate and increased sweating.

What happens when two drugs interact?

Drug interactions may lead to an increase or decrease in the beneficial or the adverse effects of the given drugs. When a drug interaction increases the benefit of the administered drugs without increasing side effects, both drugs may be combined to increase the control of the condition that is being treated.

What causes adverse drug reactions?

Factors which might increase the possibility of the occurrence of ADRs include; extremes of age, gender, multiple drugs, disease state, past history of ADR or allergy, genetic factors, large doses and many other factors.

Which drug produces Ocular toxicity?

Chlorpromazine is one of the most common psychotropic agents which can potentially induce numerous and diverse unwanted ocular effects. At high dosages, the drug can commonly cause abnormal pigmentation of the eyelids, interpalpebral conjunctiva, lens, and cornea. It can also cause corneal edema [36].