What causes Dilated Pupils?
There’s a wide variety of things that can cause dilated pupils. Here are some of the most common ones:
Medications
The following prescription and non-prescription medicines can cause your pupils to dilate and affect their ability to react to light:
• Antihistamines
• Decongestants
• Tricyclic antidepressants
• Motion sickness medicines
• Anti-nausea medicines
• Anti-seizure drugs
• Medications for Parkinson’s disease
• Botox and other medications containing botulinum toxin
• Atropine (used for myopia control and other medical purposes)
• Eye injury
A serious, penetrating eye injury can damage your iris and cause the pupil of that eye to become dilated and irregular in shape. Sometimes, this sort of injury can occur during an eye surgery, such as a complicated cataract surgery or a corneal transplant.
Brain injury or disease
A head injury, stroke or brain tumor can affect how your pupils react to light and cause dilated pupils. One or both eyes may be affected. This is why you see physicians checking an athlete’s pupils with a penlight following head trauma sustained during sports competitions, or when a patient arrives at a hospital emergency department with other possible stroke symptoms.
Recreational drug use
Research has shown that alcohol and marijuana, separately or in combination can reduce your eyes’ ability to recover from exposure to a bright light source (such as oncoming headlights at night) and adapt to changing light conditions. This effect can last two hours or longer after drug ingestion. However, these substances do not cause your pupils to dilate. A number of illegal drugs used for recreational purposes, however, cause dilated pupils and slow your eyes’ ability to react to light. These include:
• Amphetamines
• Cocaine
• LSD
• MDMA (Ecstasy)
What to do for dilated pupils
If you or someone else notices you have dilated pupils or one of your pupils looks larger than the other after head trauma, seek medical attention immediately. The same is true if you experience sudden dizziness, headache, confusion, balance problems or other symptoms of a possible stroke.
If you notice dilated pupils after you’ve started taking one of the medications noted above, call the prescribing physician for advice. In cases other than those described above, call your eye doctor immediately for advice if you notice your pupils are dilated, especially if the onset is sudden. If you don’t currently have an eye doctor near you, you can find one here.
If you have dilated pupils or your pupils react slower than normal to changing light conditions, you will be more sensitive to sunlight. Consider purchasing eyeglasses with photochromic lenses that darken automatically outdoors in daylight for greater comfort. Or purchase sunglasses with polarized lenses for optimum comfort and glare reduction in bright sunlight.
Another option to reduce photophobia caused by dilated pupils and to improve the cosmetic appearance of the eyes is to be fitted with custom prosthetic contact lenses. These lenses give the appearance of having equal pupils of normal size. Prosthetic contacts are especially beneficial for cases of aniridia and large, irregular pupils caused by trauma.
Very important: Always make sure you discuss and make decisions about your eye care based upon a formal appointment with your optician or doctor.
For more information please call us or visit
KOBRIN & MARTIN OPTOMETRISTS, SANDTON
Tel: 011 884 8413 | kobrinmartin@telkomsa.net
