Overview of Photophobia

Photophobia is an extreme sensitivity and aversion to light. While the term literally means the "fear of light," it is not an actual phobia. Rather, photophobia is due to a medical condition or medications that affect the function of the eyes and/or nervous system. In cases of eye trauma, it may affect one eye rather than both.

When you have photophobia, you may squint, your eyes may tear, and you might suddenly think that the lights are "too bright." In severe cases, you may even experience eye pain. While photophobia symptoms may be more apparent in bright sunlight, some people can experience discomfort even in moderate levels of artificial light.

This article explores the symptoms and possible causes of photophobia, It also explains how photophobia is diagnosed and ways to treat both the symptoms and underlying causes of extreme light sensitivity.

Symptoms of Photophobia

Symptoms of photophobia include:

• Sensitivity to light
• Aversion to light
• A sense that regular lighting appears excessively bright
• Seeing bright colored spots, even in the dark or with your eyes closed
• Difficulty reading or looking at pictures or text
• Pain or discomfort when looking at the light
• Squinting one or both eyes
• Forehead pain
• Tears from your eyes
• A sense that your eyes are excessively dry
• A feeling that you want to shut your eyes

Photophobia can affect people of all ages. It is often a recurrent and benign (not medically serious) experience, but it may develop due to a medical condition. You should seek medical attention if you are having photophobia for the first time because you may need treatment.

Usually, photophobia affects both eyes equally. Sometimes, however, eye problems can cause photophobia in only one eye.

What Causes Photophobia

Photophobia can have a number of different causes. Some are temporary, while others may indicate a medical problem.

Hypersensitivity to Pain

Migraines are the most common cause of recurrent photophobia. Some people experience photophobia during the prodromal phase of a migraine before it reaches its peak. However, photophobia can also accompany the most intense phase of a migraine or can occur within a day or two after a migraine resolves.

Fatigue, trigeminal neuralgia, facial neuropathy, head trauma, and fibromyalgia can all be associated with increased sensitivity to pain and discomfort, which may manifest as photophobia.

Head or Face Pain

Tension headaches, dental problems, meningitis, or optic nerve disease (such as optic neuritis due to multiple sclerosis) can all irritate your eyes, triggering photophobia. Sometimes, photophobia may be the first sign of one of these illnesses.

Eye Problems

Photophobia can be quite severe when it is caused by diseases of the eyes. In these situations, when your eyes might not adequately protect you from light, moderate light can seem unbearably bright.

Common eye conditions that cause photophobia include:

• Light-colored eyes
• Albinism
• Dry eyes
• Dilated pupils
• Corneal abrasion
• Uveitis (eye infection or inflammation)
• Cataracts
• Glaucoma
• Retinal detachment

Medications

Many medications temporarily induce photophobia. Tetracycline, an antibiotic, is commonly associated with photophobia.

Other medications that can trigger this effect include:

• Methotrexate
• Ibuprofen
• Naproxen
• Haloperidol
• Chloroquine
• Methylphenidate

Behavioral Issues

Anxiety, depression, psychosis, drug use, and drug withdrawal can all induce photophobia. Children and adults who are autistic can be hypersensitive to surrounding stimuli and are often disturbed or upset by lights, noises, or unexpected sensations.

Physiology Behind Photophobia

Some of the conditions that trigger photophobia are related to the eye itself and some affect the way the body detects pain. Conditions that affect the eye, such as dilated pupils or light-colored eyes, actually allow too much light to enter into the eyes, which is inherently unpleasant.

Migraine and trigeminal neuralgia cause the eyes and head to become so sensitive that even sensations that are not normally painful, such as touch, sounds, smells, and light can seem unusually uncomfortable. Illnesses such as meningitis, uveitis, and retinal detachment induce pain due to inflammation and injury to structures in or near the eyes, which can make normal stimuli, such as light, intolerable.

Disease or alteration of the function of the retina, which normally detects light, is believed to play a role as well.

Diagnosis

Photophobia is diagnosed by a healthcare provider, who will listen to your medical history, perform a physical examination and an eye examination, and possibly do some specialized diagnostic tests.

The first thing your healthcare provider will ask you is whether your symptoms occur all the time or at certain times. They will also ask whether you experience other symptoms along with your photophobia.

Your physical examination will include an evaluation of your neurological function including your strength, reflexes, coordination, and sensation. Your healthcare provider will also likely check your eye movements, vision, and whether your pupils (the black circles in the colored part of your eye) constrict, or become smaller, in response to light.

Your healthcare provider will also examine the retina, nerves, and blood vessels behind your eyes using ophthalmoscopy, a painless and non-invasive method of examining your eyes. Ophthalmoscopy can detect cataracts, retinal problems, nerve and blood vessel disease, or glaucoma. You may need to have your pupils dilated with medicated eye drops to make this part of your examination more sensitive.

After your physical examination, you may need other tests, depending on your complaints and any findings on your physical examination. Other tests you may need include:

• Ocular tonometry: Tonometry measures the fluid pressure within your eye, and is often used to detect glaucoma. You may briefly feel slight pressure or a warm puff of air as this device measures your eye pressure. While it is not painful or dangerous, you might receive numbing eye drops before the test to make you more comfortable.
• Optical coherence tomography (OCT): OCT is used to detect conditions such as macular degeneration and diabetic retinopathy. It is a painless and non-invasive test that produces an image of the retina using light wave technology. You might need to have your pupils dilated to make the images obtained from this test more useful.
• Fluorescein angiography: This test involves an injection of dye into a blood vessel (usually in your arm). The dye makes the blood vessels in your eye more visible. Your healthcare provider will take pictures that can detect leaking or other problems with the blood vessels in your eye.
• Blood tests: You may need to have blood tests to identify infection, inflammation, or hormonal irregularities. These results can help your healthcare provider diagnose diseases that could affect your eye, nerves, or brain.
• Brain magnetic resonance imaging (MRI): If there is concern that you could have pressure, inflammation, or an infection in or around your brain, then you may need to have a brain MRI.
• Brain magnetic resonance angiogram (MRA) or computed tomography angiogram (CTA): While a fluorescein angiography is used to look at the blood vessels in your eye, a brain MRA or CTA creates an image of the blood vessels in your brain. If there is any concern that there could be inflammation, bleeding, or blockage of the blood vessels in your brain, you may need to have one of these tests.

Treating Photophobia

Treatment of photophobia depends on the cause. When the cause is an underlying medical condition, successful treatment of that condition will help relieve your photophobia.

Diagnosing the cause of your symptoms is important because the conditions that cause photophobia are treated differently from each other.

For example, if you have optic neuritis due to MS, then you would need medication to manage MS. If you have cataracts, then you may need surgery. Photophobia can be a sign of glaucoma, and if it turns out that glaucoma is at the root of your symptoms, you may need medication or surgery. If your photophobia is caused by migraines, then you may need over-the-counter or prescription migraine treatment.

The other aspect of photophobia treatment is focused on the relief of your symptoms. While your underlying condition is being treated, it may take days or even longer for your photophobia to improve. There are several things you can do to maintain comfort while your condition is resolving.

• Wear sunglasses.
• Decrease your exposure to the light.
• Use green-tinted light or tinted glasses if possible because it does not induce photophobia to the same degree as other colors of light.
• Use eye drops for comfort.
• Take over-the-counter pain medication, such as acetaminophen or non-steroidal anti-inflammatories (NSAIDs) after discussing it with your healthcare provider.
• Discuss the pros and cons of prescription pain medication with your healthcare provider.
• Non-invasive transcutaneous electrical nerve (TENS) stimulation may provide some relief for people who have photophobia with eye pain.
• Botulinum toxin A injections have been used for photophobia that does not improve with medication, with some good results.

Be prepared to deal with photophobia from time to time if you experience recurrent migraines. Be sure to have sunglasses, a hat, and comfortable lighting within easy access so that you can minimize the burden of photophobia.

Photophobia is a troublesome symptom that can usually be managed with lifestyle adjustments, such as wearing sunglasses and dimming the lights. However, it can be a sign of a serious medical or eye problem. If you don’t have a diagnosis for the cause of your photophobia, you should seek medical attention and talk to your healthcare provider about your symptoms.