Photophobia (also light sensitivity) or fear of light, is a symptom of excessive sensitivity to light and the aversion to sunlight or well-lit places. In medical terms, it is not fear, but an experience of discomfort or pain to the eyes due to light exposure. The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10) is a coding of diseases and signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or diseases, as classified by the World Health Organization (WHO). ... // H00-H59 - Diseases of the eye and adnexa (H00-H06) Disorders of eyelid, lacrimal system and orbit (H00) Hordeolum and chalazion (H000) Hordeolum and other deep inflammation of eyelid (H001) Chalazion (H01) Other inflammation of eyelid (H010) Blepharitis (H011) Noninfectious dermatoses of eyelid (H02) Other disorders of eyelid (H020) Entropion... The International Statistical Classification of Diseases and Related Health Problems (most commonly known by the abbreviation ICD) provides codes to classify diseases and a wide variety of signs, symptoms, abnormal findings, complaints, social circumstances and external causes of injury or disease. ... The following is a list of codes for International Statistical Classification of Diseases and Related Health Problems. ... The Disease Bold textDatabase is a free website that provides information about the relationships between medical conditions, symptoms, and medications. ... MedlinePlus (medlineplus. ... Medical Subject Headings (MeSH) is a huge controlled vocabulary (or metadata system) for the purpose of indexing journal articles and books in the life sciences. ... The term symptom (from the Greek meaning chance, mishap or casualty, itself derived from συμπιπτω meaning to fall upon or to happen to) has two similar meanings in the context of physical and mental health: Strictly, a symptom is a sensation or change in health function experienced by a patient. ... The sensitivity or insensitivity of a human, often considered with regard to a particular kind of stimulus, is the strength of the feeling it results in, in comparison with the strength of the stimulus. ... This article does not cite any references or sources. ... Prism splitting light High Resolution Solar Spectrum Sunlight in the broad sense is the total spectrum of the electromagnetic radiation given off by the Sun. ...

Light sensitivity is usually due to too much light entering the eye, which causes over stimulation of the photoreceptors in the retina and subsequent excessive electric impulses to the optic nerve. This leads to a reflex aversion to light, and discomfort or pain. Too much light can enter the eye if it is damaged, such as with corneal abrasion and retinal damage, or if a pupil(s) is unable to normally constrict (seen with damage to the oculomotor nerve). Human eye cross-sectional view. ... This article is about the anatomical structure. ... The oculomotor nerve () is the third of twelve paired cranial nerves. ...

Patients with photophobia will avert their eyes from direct light (sunlight and room lights), or may seek the shelter of a dark room or wear sunglasses.

Photophobia is also a behavior demonstrated by insects or other animals which seek to stay out of the light.

Causes

Patients may develop photophobia as a result of several different medical conditions, related to the eye or the nervous system. For other uses, see Eye (disambiguation). ... The Human Nervous System. ...

• Meningitis
• Eye disease, injury, or infection such as chalazion, episcleritis, glaucoma, keratoconus
• Subarachnoid haemorrhage
• Albinism
• Burns to the eye
• Migraines
• Encephalitis
• Conjunctivitis
• Aphakia
• Iritis
• Corneal abrasion
• Corneal ulcer
• Cataracts
• Retinal detachment
• Chiari malformation
• Cystinosis
• Anticholinergic drugs may cause photophobia by paralyzing the iris sphincter muscle.
• Hangover
• Chikungunya

Meningitis is the inflammation of the protective membranes covering the central nervous system, known collectively as the meninges. ... For other uses, see Eye (disambiguation). ... A chalazion, also known as a Meibomian gland lipogranuloma, is a cyst in the eyelid that is caused by inflammation of the meibomian gland, usually on the upper eyelid. ... This article or section does not cite its references or sources. ... Keratoconus (from Greek: kerato- horn, cornea; and konos cone), is a degenerative non-inflammatory disorder of the eye in which structural changes within the cornea cause it to thin and change to a more conical shape than its normal gradual curve. ... Albino redirects here. ... For other uses, see Eye (disambiguation). ... Encephalitis is an acute inflammation of the brain, commonly caused by a viral infection. ... Aphakia is the absence of the lens of the eye, due to surgical removal, perforating wound or ulcer, or congenital anomaly; causes a loss of accommodation, hyperopia, and a deep anterior chamber. ... Iritis is a form of anterior uveitis and refers to the inflammation of the iris of the eye. ... For corneal abrasions in dogs and cats, see corneal ulcer. ... A corneal ulcer is an inflammatory condition of the cornea involving loss of its outer layer. ... Cataract is also used to mean a waterfall or where the flow of a river changes dramatically. ... Retinal detachment is a disorder of the eye in which the retina peels away from its underlying layer of support tissue. ... Arnold-Chiari malformation, sometimes referred to as the Chiari malformation, is an anomaly of the brain in which the cerebellar tonsils are elongated and pushed down through the opening of the base of the skull (see foramen magnum), blocking the flow of cerebrospinal fluid (CSF). ... Cystinosis is a hereditary disorder of the renal tubules characterized by the presence of carbohydrates and amino acids in the urine, excessive urination, and low blood levels of potassium ions and phosphates. ... An anticholinergic agent is a member of a class of pharmaceutical compounds which serve to reduce the effects mediated by acetylcholine in the central nervous system and peripheral nervous system. ... The Iris sphincter muscle is a muscle of the human body. ... For other uses, see Hangover (disambiguation). ... Chikungunya is a relatively rare form of viral fever caused by an alphavirus that is spread by mosquito bites from Aedes aegypti mosquitoes, though recent research by the Pasteur Institute in Paris claims the virus has suffered a mutation that enables it to be transmitted by Aedes albopictus (Tiger mosquito). ...

In mythology

In folklore and mythology, many creatures suffer from photophobia - or heliophobia, a specific fear of sunlight. This article does not cite any references or sources. ... For other uses, see Mythology (disambiguation). ... The English suffix -phobia is used to describe fear or hatred (the latter is often ignored) of a particular thing or subject. ...

• The Norse troll is said to either turn to stone or become trapped above ground when the sun rises.
• According to Paracelsus, gnomes explode when they go above ground ^{[citation needed]}. As C.S. Lewis puts it, "if he thrust out his face…[it] would break into splinters, bursting as a man would burst in interstellar space." - though in fact, humans exposed to the vacuum of space experience no such spectacular effect.
• In English folklore, goblins are said to be unable to bear light.
• A common element of the vampire myth says that vampires perish, generally by burning or turning to ash, when exposed to direct sunlight.
• Gargoyles are often portrayed as purely nocturnal creatures, changing into stone if the sun shines upon them
• In the story of Hercules, his twelfth labour was to capture Cerberus. In one version of this story he had only to lead Ceberus to daylight.

Norse, Viking or Scandinavian mythology comprises the indigenous pre-Christian religion, beliefs and legends of the Scandinavian peoples, including those who settled on Iceland, where most of the written sources for Norse mythology were assembled. ... For other uses, see Troll (disambiguation). ... Presumed portrait of Paracelsus, attributed to the school of Quentin Matsys. ... This article is about the mythical creature. ... Clive Staples Lewis (November 29, 1898 – November 22, 1963), commonly referred to as C. S. Lewis, was an author and scholar. ... English folklore is the folk tradition which has developed in England over a number of centuries. ... For other uses, see Goblin (disambiguation). ... Philip Burne-Jones, The Vampire, 1897 Vampires are mythological or folkloric beings that subsist on human and/or animal lifeforce. ... For other uses, see Hercules (disambiguation). ... Heracles and threatened Cerberus, Attic black-figure neck-amphora, ca. ...

In fiction

• In J.R.R. Tolkien's works, goblins are said to get wobbly legs and become giddy in the head when outside, while trolls turn to stone.
• In Lemony Snicket's A Series of Unfortunate Events, the zombies from the movie Zombies in the Snow are forced to retreat during daylit hours.
• In the films Gremlins and Gremlins 2: The New Batch, both the Mogwai and Gremlins are incredibly sensitive to bright light; direct sunlight on their skin will kill them in a matter of seconds.
• It is common tradition in literature that vampires burn and/or explode when exposed to light, which was first introduced in the 1922 German film Nosferatu. Contrary to popular thought, Bram Stoker's Dracula did not originate this convention.
• In the films 'Blade', 'Blade 2' and 'Blade 3', Wesley Snipes plays a half vampire half human, known as 'The Daywalker', i.e. a vampire that can walk in the light without fear of burning/exploding.
• A character from the anime Ouran High School Host Club, Umehito Nekozawa, avoids light, and wears a hood all the time to protect himself from it. When exposed to light for a short time, he collapses, but he eventually gets over it.
• prot (lower-case is proper) from the planet K-PAX (upper case is proper), wears dark glasses while on our planet because he can see ultraviolet light and would be blind without them.
• In the films Pitch Black and The Chronicles of Riddick, the antihero protagonist, Richard B. Riddick is photophobic as a result of medical alterations to his eyes which give him superhuman night vision, but forces him to wear welding goggles in the light.

J. R. R. Tolkien in 1916. ... Lemony Snicket is a pseudonym used by author Daniel Handler in his book series A Series of Unfortunate Events, as well as a character in that series. ... This article is about the book series. ... Zombies in the Snow is a fictional film presented as the last movie created by the fictional film director Dr. Gustav Sebald before his death in the childrens novel series, A Series of Unfortunate Events, by Lemony Snicket (a. ... For other uses, see Gremlin (disambiguation). ... The word mogwai is the transliteration of the Cantonese word 魔怪 (mo1 gwai2) (Mandarin Chinese: 魔鬼; pinyin：móguǐ) meaning ghost, evil spirit, devil or demon. // According to Chinese tradition, mogui are a breed of fairie folk that possess superpowers, which they often use to inflict harm on humans. ... Year 1922 (MCMXXII) was a common year starting on Sunday (link will display full calendar) of the Gregorian calendar. ... This article is about the 1922 silent film. ... Abraham Bram Stoker (November 8, 1847 – April 20, 1912) was an Irish writer, best remembered as the author of the influential horror novel Dracula. ... This article is about the novel. ... Wesley Trent Snipes (born July 31, 1962) is an American actor, martial artist and film producer. ... Serialized in LaLa Original run August 5, 2003 – Ongoing No. ... Book Cover K-PAX is the name of the first novel in the K-PAX trilogy by Gene Brewer and a film based on the series: K-PAX (1995) K-PAX (2001)— film K-PAX II: On a Beam of Light (2001) K-PAX III: Worlds of Prot (2002) K... This article or section does not cite its references or sources. ... The Chronicles of Riddick is a 2004 American science fiction / fantasy / thriller film. ... Wikipedia does not have an article with this exact name. ... Night-vision is seeing in the dark. ...

See also

• Heliophobia, fear of sunlight
• Photosensitivity, the amount to which an object reacts upon receiving photons of light
• Erythropoietic protoporphyria, a disease manifesting itself with painful photosensitivity
  • Photic sneeze reflex, a medical condition by which people exposed to bright light sneeze

The English suffix -phobia is used to describe fear or hatred (the latter is often ignored) of a particular thing or subject. ... Photosensitivity is the amount to which an object reacts upon receiving photons of light. ... The porphyrias are inherited or acquired disorders of certain enzymes in the heme biosynthetic pathway (also called porphyrin pathway). ... ACHOO syndrome is inherited in an autosomal dominant fashion. ...

References

Lewis, C.S. Poems: C.S. Lewis. U.S.: Harvest/HBJ, 1964. ISBN 0-15-672248-8.

External links

• Photophobia (Light Sensitivity) at allaboutvision.com
• Darker Google for light sensitive eyes