If Your Eyes Are Dilated, It Could Be A Sign Of This

Does the thought of dilated pupils immediately bring to mind an orange-haired Ziggy Stardust with his wonderfully weird eyes, or is that just us? Large, dark pupils might be considered very rock and roll, thanks to music icon David Bowie's famous feature, but what does it mean when your pupils are dilated?

You've surely noticed that your pupils regularly grow bigger and smaller, but do you know why? The size of your pupils changes in order to control how much light enters your eye. In bright light, the pupils constrict in order to prevent too much light from entering. Conversely, in the dark, they expand or dilate in order to allow more light in. If your pupils do not respond to light this way, it means that they're not functioning normally (per Cleveland Clinic.)

If your pupils are dilated without a change in light, you're experiencing a condition called mydriasis, which could be caused by certain medications, illnesses, or diseases.

Alternative reasons your pupils are dilated

There are a few common medications that can have an effect on the muscles that control your pupils, making them resistant to shrinking in the light. Some antidepressants, antihistamines, anti-nausea or motion sickness medications, anti-seizure medications, medications for Parkinson's disease, and botox are a few of the most common offenders. Of course, illegal drugs like cocaine, LSD, magic mushrooms, methamphetamines and ecstasy will also keep pupils dilated, even in bright light (per Cleveland Clinic).

Moreover, an eye injury, like the scratch that paralyzed the muscles in Mr. Bowie's left iris, might be to blame. Or more seriously, pressure from a traumatic head injury, stroke, or a brain tumor may be affecting the muscles in your iris, not allowing them to constrict. According to a study published in the International Journal of General Medicine, in the case of a 30-year-old woman, her severe migraines were associated with benign episodic unilateral mydriasis — or rather, one pupil dilating at the time of the migraine. 

When is it time to see a doctor?

If your pupils are dilated from medication, they should return to normal size after the medication wears off. If it's a prescription you're meant to take regularly, talk with your doctor about an alternative. Because your eyes are more sensitive to light when your pupils are dilated, try to avoid bright light and wear sunglasses when your eyes are dilated. Visit your eye doctor or an eye specialist if you find that one pupil is larger than the other, your dilated pupils subsist for an extended period of time, or you experience a headache or dizziness with your dilated pupils (per Medical News Today). 

If your eyes are dilated due to a head injury, seek emergency attention. A magnetic imaging test (MRI) or computed tomography (CT) scan may be taken to ensure you haven't sustained a serious injury to your brain.