Photophobia | |
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Specialty | Ophthalmology |
Photophobia is a medical symptom of abnormal intolerance to visual perception of light. [1] As a medical symptom, photophobia is not a morbid fear or phobia, but an experience of discomfort or pain to the eyes due to light exposure or by presence of actual physical sensitivity of the eyes, [2] though the term is sometimes additionally applied to abnormal or irrational fear of light, such as heliophobia. [3] The term photophobia comes from the Greek φῶς (phōs), meaning "light", and φόβος (phóbos), meaning "fear". [4] [5]
Patients may develop photophobia as a result of several different medical conditions, related to the eye, the nervous system, genetic, or other causes.
Photophobia may manifest itself in an increased response to light starting at any step in the visual system, such as:
Common causes of photophobia include migraine headaches, TMJ, cataracts, Sjögren syndrome, mild traumatic brain injury (MTBI), or severe ophthalmologic diseases such as uveitis or corneal abrasion. [6] A more extensive list follows:
Causes of photophobia relating directly to the eye itself include:
Neurological causes for photophobia include:
Treatment for light sensitivity addresses the underlying cause, whether it be an eye, nervous system or other cause. If the triggering factor or underlying cause can be identified and treated, photophobia may disappear. Tinted glasses are sometimes used. [33]
People with photophobia may feel eye pain from even moderate levels of artificial light and avert their eyes from artificial light sources. Ambient levels of artificial light may also be intolerable to persons afflicted with photophobia such that they dim or remove the light source, or go into a dimmer lit room, such a one lit by refraction of light from outside the room. Alternatively, they may wear dark sunglasses, sunglasses designed to filter peripheral light, precision tinted glasses, and/or wide-brimmed sun hats or baseball caps. Some types of photophobia may be helped with the use of precision tinted lenses which block the green-to-blue end of the light spectrum without blurring or impeding vision. [34] [35]
Other strategies for relieving photophobia include the use of tinted contact lenses and/or the use of prescription eye drops that constrict the pupil, thus reducing the amount of light entering the eye. Such strategies may be limited by the amount of light needed for proper vision under given conditions, however. Dilating drops may also help relieve eye pain from muscle spasms or seizures triggered by lighting/migraine, allowing a person to "ride out the migraine" in a dark or dim room. A paper by Stringham and Hammond, published in the Journal of Food Science , reviews studies of effects of consuming Lutein and Zeaxanthin on visual performance, and notes a decrease in sensitivity to glare. [36]
Photophobia may preclude or limit a person from working in places where lighting is used, unless the person is able to obtain a reasonable accommodation like being allowed to wear tinted glasses. Some people with photophobia may thereby be better able to work at night or be more easily accommodated in the workplace at night.
Outdoor night lighting may be equally offensive for persons with photophobia, however, given the wide variety of bright lighting used for illuminating residential, commercial and industrial areas, such as LED (light-emitting diode) lamps. [37] [38]
The increasing popularity of "overpoweringly intense" LED headlights being used on "pickups and S.U.V.s" has prompted more frequent reports of photophobia among motorists, cyclists, and pedestrians. [39]
Headache, also known as cephalalgia, is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in those with severe headaches.
Keratoconus (KC) is a disorder of the eye that results in progressive thinning of the cornea. This may result in blurry vision, double vision, nearsightedness, irregular astigmatism, and light sensitivity leading to poor quality-of-life. Usually both eyes are affected. In more severe cases a scarring or a circle may be seen within the cornea.
The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Along with the anterior chamber and lens, the cornea refracts light, accounting for approximately two-thirds of the eye's total optical power. In humans, the refractive power of the cornea is approximately 43 dioptres. The cornea can be reshaped by surgical procedures such as LASIK.
Keratitis is a condition in which the eye's cornea, the clear dome on the front surface of the eye, becomes inflamed. The condition is often marked by moderate to intense pain and usually involves any of the following symptoms: pain, impaired eyesight, photophobia, red eye and a 'gritty' sensation.
Visual snow syndrome (VSS) is a form of visual hallucination that is characterized by the perception of small, bilateral, simultaneous, diffuse, mobile, asynchronous dots usually throughout the entire visual field, but it can be partial, and it is present in all conditions of illumination, even with the eyes closed. The dots remain individual and do not clump together or change in size. Visual snow exists in one of two forms: the pulse type and the broadband type.
Dry eye syndrome, also known as keratoconjunctivitis sicca, is the condition of having dry eyes. Symptoms include dryness in the eye, irritation, redness, discharge, blurred vision, and easily fatigued eyes. Symptoms range from mild and occasional to severe and continuous. Dry eye syndrome can lead to blurred vision, instability of the tear film, increased risk of damage to the ocular surface such as scarring of the cornea, and changes in the eye including the neurosensory system.
Diplopia is the simultaneous perception of two images of a single object that may be displaced horizontally or vertically in relation to each other. Also called double vision, it is a loss of visual focus under regular conditions, and is often voluntary. However, when occurring involuntarily, it results in impaired function of the extraocular muscles, where both eyes are still functional, but they cannot turn to target the desired object. Problems with these muscles may be due to mechanical problems, disorders of the neuromuscular junction, disorders of the cranial nerves that innervate the muscles, and occasionally disorders involving the supranuclear oculomotor pathways or ingestion of toxins.
A red eye is an eye that appears red due to illness or injury. It is usually injection and prominence of the superficial blood vessels of the conjunctiva, which may be caused by disorders of these or adjacent structures. Conjunctivitis and subconjunctival hemorrhage are two of the less serious but more common causes.
Irlen syndrome, also referred to as scotopic sensitivity syndrome (SSS), visual stress, or Meares–Irlen syndrome, is a light-based visual processing disorder. Many mainstream professionals are skeptical of the concept; however, current neuroscience research has successfully documented differences in brain function among this population versus those without the condition. Early research on Irlen syndrome produced mixed results; however, the overwhelming majority of studies conducted over the last 40 years have documented the benefits of using precision-tinted colored lenses to address a variety of related symptomology, including: reduction in physical symptoms that include headaches, migraines, eye strain, fatigue, and light sensitivity; and improved functioning and success in both academia and the workplace.
Recurrent corneal erosion is a disorder of the eyes characterized by the failure of the cornea's outermost layer of epithelial cells to attach to the underlying basement membrane. The condition is excruciatingly painful because the loss of these cells results in the exposure of sensitive corneal nerves. This condition can often leave patients with temporary blindness due to extreme light sensitivity (photophobia).
Corneal abrasion is a scratch to the surface of the cornea of the eye. Symptoms include pain, redness, light sensitivity, and a feeling like a foreign body is in the eye. Most people recover completely within three days.
An aura is a perceptual disturbance experienced by some with epilepsy or migraine. An epileptic aura is a seizure.
A scleral lens, also known as a scleral contact lens, is a large contact lens that rests on the sclera and creates a tear-filled vault over the cornea. Scleral lenses are designed to treat a variety of eye conditions, many of which do not respond to other forms of treatment.
Polycoria is a pathological condition of the eye characterized by more than one pupillary opening in the iris. It may be congenital or result from a disease affecting the iris. It results in decreased function of the iris and pupil, affecting the physical eye and visualization.
Corneal ulcer, also called keratitis, is an inflammatory or, more seriously, infective condition of the cornea involving disruption of its epithelial layer with involvement of the corneal stroma. It is a common condition in humans particularly in the tropics and in farming. In developing countries, children afflicted by vitamin A deficiency are at high risk for corneal ulcer and may become blind in both eyes persisting throughout life. In ophthalmology, a corneal ulcer usually refers to having an infection, while the term corneal abrasion refers more to a scratch injury.
Irlen spectral filters or Irlen lenses are coloured overlay filters or tinted lenses crafted specifically for the wearer and worn as glasses or contact lenses. They are intended to help people with the supposed perceptual processing difficulty known as Irlen syndrome, also known as scotopic sensitivity syndrome or visual stress, in which sensitivity to specific wavelengths of light provokes difficulty and discomfort when performing visually intensive activities such as reading. The existence of Irlen syndrome is controversial. The Royal Australian and New Zealand College of Ophthalmologists (RANZCO) came out strongly against Irlen syndrome, saying there was no evidence the condition existed or the treatment of reading difficulties with Irlen lenses worked. However, there is a small body of research supporting the use of colour to alleviate the symptoms associated with Irlen syndrome.
Macular corneal dystrophy, also known as Fehr corneal dystrophy, is a rare pathological condition affecting the stroma of cornea first described by Arthur Groenouw in 1890. Signs are usually noticed in the first decade of life and progress afterwards, with opacities developing in the cornea and attacks of pain. This gradual opacification leads to visual impairment often requiring keratoplasty in the later decades of life.
Granular corneal dystrophy is a slowly progressive corneal dystrophy that most often begins in early childhood.
Primary juvenile glaucoma is a subtype of primary congenital glaucoma that develops due to ocular hypertension and is diagnosed between three years of age and early adulthood. It is caused due to abnormalities in the anterior chamber angle development that obstruct aqueous outflow in the absence of systemic anomalies or other ocular malformation.
Ocular neuropathic pain is a spectrum of disorders of ocular pain which are caused by damage or disease affecting the nerves. Ocular neuropathic pain is frequently associated with damaged or dysfunctional corneal nerves, but the condition can also be caused by peripheral or centralized sensitization. The condition shares some characteristics with somatic neuropathic pain in that it is similarly associated with abnormal sensations (dysesthesia) or pain from normally non-painful stimuli (allodynia), but until recent years has been poorly understood by the medical community, and frequently dismissed by ophthalmologists who were not trained to identify neuropathic pain as a source of unexplained eye pain beyond objective findings noted on slit-lamp examination.