Light sensitivity or photosensitivity refers to a notable or increased reactivity to light. Apart from

vision Vision, Visions, or The Vision may refer to: Perception Optical perception * Visual perception, the sense of sight * Visual system, the physical mechanism of eyesight * Computer vision, a field dealing with how computers can be made to gain und ...

, human beings have many physiological and psychological responses to light. In rare individuals an atypical response may result in serious discomfort, disease, or injury. Some drugs have a photosensitizing effect. Properties of natural or artificial light that may abnormally affect people include: * Timing of light (upset of normal

circadian rhythm A circadian rhythm (), or circadian cycle, is a natural oscillation that repeats roughly every 24 hours. Circadian rhythms can refer to any process that originates within an organism (i.e., Endogeny (biology), endogenous) and responds to the env ...

s, seasonal affective disorder, sleep disorders) * Intensity of light (

photophobia Photophobia is a medical symptom of abnormal intolerance to visual perception of light. 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 o ...

sunburn Sunburn is a form of radiation burn that affects living tissue, such as skin, that results from an overexposure to ultraviolet (UV) radiation, usually from the Sun. Common symptoms in humans and other animals include red or reddish skin tha ...

skin cancer Skin cancers are cancers that arise from the Human skin, skin. They are due to the development of abnormal cells (biology), cells that have the ability to invade or metastasis, spread to other parts of the body. It occurs when skin cells grow ...

) * Wavelength of light (in

lupus Lupus, formally called systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Common ...

urticaria Hives, also known as urticaria, is a kind of skin rash with red or flesh-colored, raised, itchy bumps. Hives may burn or sting. The patches of rash may appear on different body parts, with variable duration from minutes to days, and typically ...

) * Rapid flickers in intensity of light may trigger or aggravate photosensitive epilepsy,

epileptic seizure A seizure is a sudden, brief disruption of brain activity caused by abnormal, excessive, or synchronous neuronal firing. Depending on the regions of the brain involved, seizures can lead to changes in movement, sensation, behavior, awareness, o ...

, or

migraine Migraine (, ) is a complex neurological disorder characterized by episodes of moderate-to-severe headache, most often unilateral and generally associated with nausea, and light and sound sensitivity. Other characterizing symptoms may includ ...

headaches.Light and Sensitivity
headaches.org. Retrieved 11 January 2019. Conditions that may include sensitivity to light include

vertigo Vertigo is a condition in which a person has the sensation that they are moving, or that objects around them are moving, when they are not. Often it feels like a spinning or swaying movement. It may be associated with nausea, vomiting, perspira ...

and

chronic fatigue syndrome Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a disabling Chronic condition, chronic illness. People with ME/CFS experience profound fatigue that does not go away with rest, as well as sleep issues and problems with memory ...

. Controlled application of artificial light can be used in a program of

light therapy Light therapy, also called phototherapy or bright light therapy is the exposure to direct sunlight or artificial light at controlled wavelengths in order to treat a variety of medical disorders, including seasonal affective disorder (SAD), circ ...

to treat some disorders.

Sunlight

Sunlight, especially its

ultraviolet radiation Ultraviolet radiation, also known as simply UV, is electromagnetic radiation of wavelengths of 10–400 nanometers, shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight and constitutes about 10% of t ...

component, can cause increased or additional types of damage in predisposed individuals, such as those taking certain phototoxic drugs, or those with certain conditions associated with photosensitivity, including: *

Psoriasis Psoriasis is a long-lasting, noncontagious autoimmune disease characterized by patches of abnormal skin. These areas are red, pink, or purple, dry, itchy, and scaly. Psoriasis varies in severity from small localized patches to complete b ...

European Guidelines for Photodermatoses > 2 Photoaggravated Disorders
at European Dermatology Forum * Atopic eczema *

Mastocytosis Mastocytosis, a type of mast cell A mast cell (also known as a mastocyte or a labrocyte) is a resident cell of connective tissue that contains many granules rich in histamine and heparin. Specifically, it is a type of granulocyte derived from ...

* Mast cell activation syndrome * Histamine intolerance * Erythema multiforme *

Seborrhoeic dermatitis Seborrhoeic dermatitis (also spelled seborrheic dermatitis in American English) is a long-term skin disorder. Symptoms include flaky, scaly, greasy, and occasionally itchy and inflamed skin. Areas of the skin rich in oil-producing glands are ...

*Autoimmune bullous diseases ( immunobullous diseases) * Mycosis fungoides *

Smith–Lemli–Opitz syndrome Smith–Lemli–Opitz syndrome is an inborn error of metabolism, inborn error of cholesterol synthesis. It is an autosome, autosomal recessive (genetics), recessive, multiple malformation syndrome caused by a mutation in the enzyme 7-Dehydrochole ...

Porphyria cutanea tarda Porphyria cutanea tarda (PCT) is a type of longterm porphyria characterised by fragile skin and sore blisters in areas of skin that receive higher levels of exposure to sunlight, such as the face and backs of the hands. These blisters burst easily ...

Xeroderma pigmentosum Xeroderma pigmentosum (XP) is a genetic disorder in which there is a decreased ability to repair DNA damage such as that caused by ultraviolet (UV) light. Symptoms may include a severe sunburn after only a few minutes in the sun, freckling in su ...

Also, many conditions are aggravated by strong light, including: *

Systemic lupus erythematosus Lupus, formally called systemic lupus erythematosus (SLE), is an autoimmune disease in which the body's immune system mistakenly attacks healthy tissue in many parts of the body. Symptoms vary among people and may be mild to severe. Common ...

Sjögren syndrome Sjögren is a Swedish surname. Notable people with the surname include: * Anders Johan Sjögren (1794–1855), Finnish linguist, historian, ethnographer and explorer * Ann Mari Sjögren, Swedish fantasy artist and illustrator * Christer Sjögren, ...

* Sinear–Usher syndrome *

Rosacea Rosacea is a long-term skin condition that typically affects the face. It results in redness, pimples, swelling, and small and superficial dilated blood vessels. Often, the nose, cheeks, forehead, and chin are most involved. A red, en ...

Dermatomyositis Dermatomyositis (DM) is a Chronic condition, long-term inflammatory disorder, inflammatory Autoimmune disease, autoimmune disorder which affects the skin and the muscles. Its symptoms are generally a skin rash and worsening muscle weakness over ...

* Darier's disease * Kindler–Weary syndrome

Fluorescent and LED lamps

The

Scientific Committee on Emerging and Newly Identified Health Risks The Scientific Committee on Emerging and Newly Identified Health Risks (SCENIHR) is one of the independent scientific committees managed by the Directorate-General for Health and Consumer Protection of the European Commission, which provide scien ...

(SCENIHR) in 2008 reviewed the connections between light from

fluorescent lamp A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. An electric current in the gas excites mercury vapor, to produce ultraviolet and make a phosphor ...

s, especially from

compact fluorescent lamp A compact fluorescent lamp (CFL), also called compact fluorescent light, energy-saving light and compact fluorescent tube, is a fluorescent lamp designed to replace an incandescent light bulb; some types fit into light fixtures designed for incan ...

, and numerous human diseases, with results including: * The inner-ear condition

Ménière's disease Ménière's disease (MD) is a disease of the inner ear that is characterized by potentially severe and incapacitating episodes of vertigo, tinnitus, hearing loss, and a feeling of fullness in the ear. Typically, only one ear is affected in ...

can be aggravated by flicker. Sufferers of

are recommended to not use fluorescent lights. * Polymorphous light eruption is a condition affecting the skin thought to be caused by an adverse reaction to ultraviolet light. Its prevalence across Europe is 10-20% of the population. Artificial light sources may provoke the condition, and compact fluorescent light have been shown to produce an eruption. * Chronic actinic dermatitis is a condition where a subject's skin becomes inflamed due to a reaction to sunlight or artificial light. Its prevalence in

Scotland Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac ...

is 16.5 per 100,000 population. There is evidence that compact fluorescent light can worsen the condition. * With the autoimmune disease

, exposure to compact fluorescent lamps will induce disease activity in photosensitive SLE patients. * There is evidence that actinic prurigo is worsened by compact fluorescent light. This disease affects 3.3% of the general population. * 3.1% of the population suffer from solar urticaria, a skin disorder affected by ultraviolet light. Some patients are directly affected by compact fluorescent light. *

Phytophotodermatitis Phytophotodermatitis, also known as berloque dermatitis,, margarita photodermatitis,, lime disease or lime phytodermatitis is a cutaneous phototoxic inflammatory reaction resulting from contact with a light-sensitizing botanical agent (such as ...

may be aggravated by the additional levels of ultraviolet light emitted by compact fluorescent light. * Patients undergoing

photodynamic therapy Photodynamic therapy (PDT) is a form of phototherapy involving light and a photosensitizing chemical substance used in conjunction with molecular oxygen to elicit cell death ( phototoxicity). PDT is used in treating acne, wet age-related macula ...

are at additional risk of adverse photosensitive reactions caused by compact fluorescent light. * One cause of

cataract A cataract is a cloudy area in the lens (anatomy), lens of the eye that leads to a visual impairment, decrease in vision of the eye. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colours, blurry or ...

s is exposure to ultraviolet light. Provided the level of UV emission from lamps is within safe limits, and the lamp a sufficient distance away from the individual, there should be no increased risk of developing cataracts. *

Photophobia Photophobia is a medical symptom of abnormal intolerance to visual perception of light. 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 o ...

is a symptom of excessive sensitivity to light which affects 5 to 20% of the population. Studies have shown that fluorescent lighting (which flickers 100 times a second) is twice as likely to cause headaches in office workers as non-flickering lights.Arnold J. Wilkins
"The Scientific Reason You Don't Like LED Bulbs—and the Simple Way to Fix Them"
''

Scientific American ''Scientific American'', informally abbreviated ''SciAm'' or sometimes ''SA'', is an American popular science magazine. Many scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it, with more than 150 Nobel Pri ...

'', 1 August 2017. Retrieved 11 June 2019. * No similar studies have been conducted into the effect of LED (light-emitting diode) lights on sufferers of photophobia but, because LED flickering is "even more pronounced", it is possible that LED lights are "even more likely to cause headaches". * There is evidence that flicker can cause

seizures A seizure is a sudden, brief disruption of brain activity caused by abnormal, excessive, or synchronous neuronal firing. Depending on the regions of the brain involved, seizures can lead to changes in movement, sensation, behavior, awareness, o ...

in patients with photosensitive epilepsy, but there has yet to be any evidence to date attributing seizures to compact fluorescent lamps. * Self-reporting suggests fluorescent lamps aggravate

dyslexia Dyslexia (), previously known as word blindness, is a learning disability that affects either reading or writing. Different people are affected to different degrees. Problems may include difficulties in spelling words, reading quickly, wri ...

References

{{reflist Skin conditions resulting from physical factors Light therapy

Sunlight

Fluorescent and LED lamps

See also

References