Photophobia or light sensitivity usually affects both eyes. However, thousands of people have reported light sensitivity in one eye, or that they feel it more in one eye more than the other (i.e. unilaterally). Whether your light sensitivity affects both eyes or just one, it can still lead to migraines, discomfort, dizziness, nausea, blurry vision, and more.
Unilateral photophobia hasn’t been widely studied. In fact, some doctors are skeptical that it occurs at all, given the lack of research and less-than-perfect patient recollection. But if you experience unilateral photophobia, you’d probably like to know what causes it, and what you can do about it.
Causes of Light Sensitivity in One Eye
Light sensitivity in one eye, also known as unilateral photophobia, could be caused by a number of circumstances or conditions such as eye infection, eye injury, cluster headaches, glaucoma, iritis, or a corneal ulcer.
If any of these sound familiar, it’s probably a good idea to visit with your eye doctor to rule out anything serious.
Eye Infection
An infection in the iris, cornea, or other parts of one eye, then it stands to reason that light sensitivity in one eye could result. Symptoms of eye infection might overlap some of the symptoms of photophobia, so keep an eye out (see what we did there?) for the following, especially anything new. Call your doctor if you think you might have an eye infection. Symptoms include:
- Redness or inflammation in or around the eye
- Increased tear production
- Eye pain or itching
- Feeling of something in the eye
- Eye swelling
- Inability to open the eye completely
- Eye discharge
Eye Injury
If you experience physical trauma in one eye, this could cause unilateral light sensitivity. Maybe the ball hit your eye during a game of H-O-R-S-E. Maybe you got something in your eye that scratched your cornea. Or perhaps you or someone else accidentally poked you in the eye. After the discomfort of the injury itself subsides, you could be left with light sensitivity in that eye.
If you sustain an eye injury, it’s important to be seen by your eye doctor as soon as you can. If you delay treatment, you may compromise your doctor’s ability to treat you properly.
Neurological Conditions
Since light sensitivity is related to how light is transmitted through the eye to the brain, there could be a neurological component to unilateral sensitivity. For example, cluster headaches may bring on unilateral light sensitivity in almost 50% of patients. As opposed to those who suffer from chronic or episodic migraine, cluster headache sufferers may be more likely to experience light sensitivity in one eye.
Eye Conditions
In their early stages, some eye conditions appear to affect just one eye. Glaucoma, which happens due to increased pressure in the eye, is a good example of this. Glaucoma may be worse in one eye than the other, causing light sensitivity to be unequal. Generally speaking though, glaucoma will impact both eyes over time.
Iritis is inflammation in the iris, and may affect one eye. When this happens, the resulting sensitivity to light may be felt just in the affected eye. Iritis has many potential causes, such as injury, infection, genetics, and some medications.
A corneal ulcer may also cause light sensitivity in one eye. These sores or abrasions may result from an eye injury or from fungal, viral, or bacterial infection. Corneal ulcer symptoms include pain, excessive tearing, redness, blurry vision, or a feeling of something in the eye. They can usually be treated by medications, or an eye patch to let the eye heal.
Foreign Objects
If you’ve ever had a speck of dust or eyelash in your eye, you’ve probably experienced light sensitivity in one eye. That sensitivity can make it tough to look in the mirror and fish the object out. If one of your eyes is irritated and sensitive to light, try flushing it with clean water to see if you can dislodge something that doesn’t belong there. If you feel like there is something in your eye and can’t get it out, visit your doctor.
How to Deal With Light Sensitivity in One Eye
Whether your light sensitivity affects one or both eyes, Axon Optics with Avulux® light sensitivity lenses may be a helpful tool. They work by filtering up to 97% of the harmful blue, amber, and red light while allowing more than 70% of the soothing green light in. They have been shown to help 90% of users. Plus, they’re portable and stylish.
Other coping strategies include:
- Eliminating or reducing exposure to fluorescent lights or LED lighting
- Avoiding eye strain
- Protecting your eyes from sunlight
- Medications
Especially if you’re feeling it in just one eye, your photophobia should be evaluated by an eye doctor. Further investigation may be needed to rule out a serious eye or neurological condition. While the cause is most likely simple and temporary, treatment may be needed.
References
Wu Y, Hallett M. Photophobia in neurologic disorders. Translational Neurodegeneration. 2017;6:26. doi:10.1186/s40035-017-0095-3.
duToit N*, Mustak H, Levetan C, and Cook C. Visual Outcomes as a Result of Time Delays from Trauma to Surgery in Cases of Open Globe Injury at Groote Schuur Hospital. Ophthalmology, Department of Surgery, University of Cape Town and Groote Schuur Hospital, South Africa
Irimia P, Cittadini E, Paemeleire K, Cohen AS, Goadsby PJ. Unilateral photophobia or phonophobia in migraine compared with trigeminal autonomic cephalalgias. Cephalalgia. 2008 Jun;28(6):626-30. doi: 10.1111/j.1468-2982.2008.01565.x. Epub 2008 Apr 16.
Bahra A, May A, Goadsby PJ. Cluster headache: a prospective clinical study with diagnostic implications. Neurology. 2002 Feb 12;58(3):354-61.
