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 un ...

, 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, internal process that regulates the sleep–wake cycle and repeats roughly every 24 hours. It can refer to any process that originates within an organism (i.e., Endogeny (biology), endogeno ...

seasonal affective disorder Seasonal affective disorder (SAD) is a mood disorder subset, in which people who have normal mental health throughout most of the year exhibit depressive symptoms at the same time each year. Common symptoms include sleeping too much, having li ...

, 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 of ...

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 animals include: red or reddish skin that is ho ...

skin cancer Skin cancers are cancers that arise from the skin. They are due to the development of abnormal cells that have the ability to invade or spread to other parts of the body. There are three main types of skin cancers: basal-cell skin cancer (BCC) ...

) * Wavelength of light (in

lupus Lupus, technically known as 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. Comm ...

urticaria Hives, also known as urticaria, is a kind of skin rash with red, 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 does not leave any long-lasti ...

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

photosensitive epilepsy Photosensitive epilepsy (PSE) is a form of epilepsy in which seizures are triggered by visual stimuli that form patterns in time or space, such as flashing lights; bold, regular patterns; or regular moving patterns. PSE affects approximately o ...

epileptic seizure An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with los ...

, or

migraine Migraine (, ) is a common neurological disorder characterized by recurrent headaches. Typically, the associated headache affects one side of the head, is pulsating in nature, may be moderate to severe in intensity, and could last from a few hou ...

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

vertigo Vertigo is a condition where a person has the sensation of movement or of surrounding objects moving when they are not. Often it feels like a spinning or swaying movement. This may be associated with nausea, vomiting, sweating, or difficulties w ...

and

chronic fatigue syndrome Chronic fatigue syndrome (CFS), also called myalgic encephalomyelitis (ME) or ME/CFS, is a complex, debilitating, long-term medical condition. The causes and mechanisms of the disease are not fully understood. Distinguishing core symptoms are ...

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

light therapy Light therapy, also called phototherapy or bright light therapy is intentional daily exposure to direct sunlight or similar-intensity artificial light in order to treat medical disorders, especially seasonal affective disorder (SAD) and circadi ...

to treat some disorders.

Sunlight

Sunlight, especially its

ultraviolet radiation Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation i ...

component, can cause increased or additional types of damage in predisposed individuals, such as those taking certain

phototoxic Phototoxicity, also called photoirritation, is a chemically induced skin irritation, requiring light, that does not involve the immune system. It is a type of photosensitivity. The skin response resembles an exaggerated sunburn. The involved chemi ...

drugs, or those with certain conditions associated with photosensitivity, including: *

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

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

Atopic eczema Atopic dermatitis (AD), also known as atopic eczema, is a long-term type of inflammation of the skin (dermatitis). It results in itchy, red, swollen, and cracked skin. Clear fluid may come from the affected areas, which often thickens over time ...

Mastocytosis Mastocytosis, a type of mast cell disease, is a rare disorder affecting both children and adults caused by the accumulation of functionally defective mast cells (also called ''mastocytes'') and CD34+ mast cell precursors. People affected by masto ...

Mast cell activation syndrome Mast cell activation syndrome (MCAS) is a type of mast cell activation disorder (MCAD), and is an immunological condition in which mast cells inappropriately and excessively release chemical mediators, resulting in a range of chronic symptoms, ...

Histamine intolerance Histamine intolerance, sometimes called histaminosis, is an over-accumulation of dietary histamine in the human body. Histamine intolerance is sometimes informally called an allergy; however, the intolerance is technically caused by the gradual ac ...

Erythema multiforme Erythema multiforme (EM) is a skin condition that appears with red patches evolving into target lesions, typically on both hands. It is a type of erythema possibly mediated by deposition of immune complexes (mostly IgM-bound complexes) in the s ...

Seborrhoeic dermatitis Seborrhoeic dermatitis, sometimes inaccurately referred to as seborrhoea, is a long-term skin disorder. Symptoms include red, scaly, greasy, itchy, and inflamed skin. Areas of the skin rich in oil-producing glands are often affected including the ...

*Autoimmune bullous diseases ( immunobullous diseases) *

Mycosis fungoides Mycosis fungoides, also known as Alibert-Bazin syndrome or granuloma fungoides, is the most common form of cutaneous T-cell lymphoma. It generally affects the skin, but may progress internally over time. Symptoms include rash, tumors, skin lesion ...

Smith–Lemli–Opitz syndrome Smith–Lemli–Opitz syndrome is an inborn error of cholesterol synthesis. It is an autosomal recessive, multiple malformation syndrome caused by a mutation in the enzyme 7-Dehydrocholesterol reductase encoded by the DHCR7 gene. It causes a bro ...

Porphyria cutanea tarda Porphyria cutanea tarda is the most common subtype of porphyria. The disease is named because it is a porphyria that often presents with skin manifestations later in life. The disorder results from low levels of the enzyme responsible for the fift ...

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

Systemic lupus erythematosus Lupus, technically known as 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. Comm ...

Sjögren syndrome Sjögren syndrome or Sjögren's syndrome (SjS, SS) is a Chronic disease, long-term autoimmune disease that affects the body's moisture-producing (lacrimal and salivary) glands, and often seriously affects other organ systems, such as the lungs, k ...

* 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, enlarg ...

Dermatomyositis Dermatomyositis (DM) is a long-term inflammatory disorder which affects skin and the muscles. Its symptoms are generally a skin rash and worsening muscle weakness over time. These may occur suddenly or develop over months. Other symptoms may inc ...

Darier's disease Darier's disease (DAR) is an inherited skin disorder that presents with multiple greasy, crusting, thick brown bumps that merge into patches. It is an autosomal dominant disorder discovered by French dermatologist Ferdinand-Jean Darier. Darier's ...

Kindler–Weary syndrome Kindler syndrome (also known as "bullous acrokeratotic poikiloderma of Kindler and Weary",) is a rare congenital disease of the skin caused by a mutation in the KIND1 gene. Symptoms and signs Infants and young children with Kindler syndrome hav ...

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 scienti ...

(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, which produces short-wave ultraviolet lig ...

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 inca ...

, 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 initial ...

can be aggravated by flicker. Sufferers of

are recommended to not use fluorescent lights. *

Polymorphous light eruption Polymorphous light eruption (PLE) presents with itchy red small bumps on sun-exposed skin, particularly face, neck, forearms and legs. It generally appears 30 minutes to a few hours after sun exposure and may last between one and 14 days. The b ...

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 country that is part of the United Kingdom. Covering the northern third of the island of Great Britain, mainland Scotland has a border with England to the southeast and is otherwise surrounded by the Atlantic Ocean to the ...

is 16.5 per 100,000 population. There is evidence that compact fluorescent light 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 Solar urticaria (SU) is a rare condition in which exposure to ultraviolet or UV radiation, or sometimes even visible light, induces a case of urticaria or hives that can appear in both covered and uncovered areas of the skin. It is classified as a ...

, a skin disorder affected by ultraviolet light. Some patients are directly affected by compact fluorescent light. *

Phytophotodermatitis Phytophotodermatitis, also known as berloque dermatitis or margarita photodermatitis, is a cutaneous phototoxic inflammatory reaction resulting from contact with a light-sensitizing botanical agent followed by exposure to ultraviolet light (from t ...

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 popularly used in treating acne. It is used cl ...

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 of the eye that leads to a decrease in vision. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colors, blurry or double vision, halos around light, trouble w ...

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 of ...

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 famous scientists, including Albert Einstein and Nikola Tesla, have contributed articles to it. In print since 1845, it i ...

'', 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 An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or neural oscillation, synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much o ...

in patients with

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

dyslexia Dyslexia, also known until the 1960s as word blindness, is a disorder characterized by reading below the expected level for one's age. Different people are affected to different degrees. Problems may include difficulties in spelling words, r ...

References

{{reflist Skin conditions resulting from physical factors Light therapy

Sunlight

Fluorescent and LED lamps

See also

References