Photophobia refers to an increased sensitivity to light, which can result in pain or avoidance. People with the condition feel that normal light is too bright.
The condition present with a heightened sensitivity to light. As the term derives from the Greek words “photo,” meaning light, and “phobia,” meaning fear, it literally denotes a fear of light.
The abnormal response to light varies among individuals. According to a 2017 study, the sensitivity may manifest as pain or discomfort in the eyes or an avoidance reaction.
Causes
Some conditions and several medications can cause photophobia, according to older research from 2012. In addition, certain types of lighting are more likely to trigger it.
Migraine headaches and dry eyes are also common causes of photophobia. Additional causes include an array of other disorders that affect the neurological system, eyes, and mental health.
Conditions
Photophobia is a symptom of some conditions affecting the neurological system, the eyes, and mental health.
These include:
Neurological conditions
Migraine headaches are the most common neurological disorder that can cause photophobia, as this condition occurs in 80–90% of people with the headaches. It happens during the headaches as well as between them.
In fact, the American Migraine Foundation (AMF) notes that photophobia is so common in individuals with migraine headaches that it is one of the criteria doctors use in the diagnosis of migraines.
Other neurological conditions that can cause photophobia include:
Blepharospasm: This term describes the involuntary blinking, closure, and squeezing of the eyelids.
Traumatic brain injuries: These are serious injuries to the brain that affect how it works.
Meningitis: This condition results in the inflammation of the protective covering of the brain.
Eye conditions
The most common eye condition that may cause photophobia is dry eyes. This occurs when a person’s tear production is inadequate to provide optimal lubrication.
Other eye conditions that may cause photophobia include:
Conjunctivitis, which is inflammation of the conjunctiva, the tissue covering the white parts of the eye
Corneal disease, which is the term for disorders affecting the cornea, the tissue covering the iris and pupil
Optic neuritis, which is inflammation of the optic nerve
Uveitis, an inflammation that occurs inside the eye and can be associated with autoimmune disorders
Psychological conditions
Several psychological conditions may cause photophobia. They include:
agoraphobia, which is the fear of being in a crowd or leaving one’s home, depression, anxiety and panic disorders
Medications
Photophobia can be a side effect of the following medications:
Benzodiazepines, which are Antianxiety drugs, such as diazepam (Valium)
Barbiturates, which are drugs that produce sedation, such as Amobarbital (Amytal)
Haloperidol (Haldol), which treats certain mental health conditions
Chloroquine (Aralen), an Antimalarial drug
Light triggers
According to the AMF, the brighter the light, and the more discomfort a person feels. Blue-light wavelength also produces more sensitivity than other wavelengths. Other triggers include flickering light and light in striped patterns. The Vestibular Disorders Association (VeDA) adds that florescent lights may also act as a trigger.
Symptoms
Photophobia may cause or worsen pain or physical discomfort in the eye. It may also produce avoidance, a reaction that stems from a feeling that normal light is overly bright. Symptoms of avoidance may include: squinting, blinking frequently and finding strong sunlight or indoor light bothersome
A person with photophobia may have a preference for: cloudy days over sunny days, dimly lit rooms over brightly lit rooms, going out after dusk rather than during the day.
Treatment
There is little evidence indicating that systemic medication can relieve photophobia. With this in mind, the focus of treatment involves alleviating the underlying condition that is causing the photophobia. If the condition causing the photophobia improves, then the photophobia may decrease as well. This strategy may involve medications, such as:
Triptans, such as Sumatriptan (Imitrex), which are drugs for migraine headaches that quiet overactive pain nerves
Botulinum toxin (Botox) to treat Blepharospasm
Benzodiazepines, such as diazepam (Valium), to relieve anxiety
Artificial tears, gels, and ointments for dry eyes
Steroid eye drops to treat Uveitis
The use of eyeglasses in a rose-colored tint called FL-41 may help some people, as it blocks blue-light wavelengths.
Prevention
The VeDA recommends that people take steps to reduce or prevent photophobia. These include:
Wearing a hat, cap, or glare-reducing sunglasses outdoors
Allowing as much natural light as possible indoors
Avoiding using florescent lights indoors
Reducing the brightness setting of electronic devices, such as TVs, phones, and computers
Avoiding wearing sunglasses indoors because chronic darkness increases sensitivity to light
Using specialized lenses that filter out the most problematic light wavelengths
In addition, the AMF suggests slowly building exposure to light to increase tolerance. In the workplace or in the home, this could involve sitting close to a window. It may also help to use light bulbs that emit only green light because green is a wavelength of light that does not trigger a migraine.
