View source for Photophobia

{{short description|Abnormal intolerance to visual perception of light}}
{{About|the human medical symptom|the biological or botanical behavioral property|Photophobia (biology)|the morbid fear of light|Heliophobia|the 2023 film|Photophobia (film)}}
{{Use mdy dates|date=September 2024}}
{{Infobox medical condition
| name          = Photophobia
| synonyms      =
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| pronounce     =
| field         = [[Ophthalmology]]
| symptoms      = Low tolerance to light on eyes, eye pain
| complications =
| onset         =
| duration      =
| types         =
| causes        =
| risks         = [[Albinism]], corneal abrasion, ocular nerve damage
| diagnosis     =
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| prevention    =
| treatment     = treatment of underlying cause, [[sunglasses]]
| medication    =
| prognosis     =
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}}

'''Photophobia''' is a medical [[symptom]] of abnormal intolerance to visual perception of [[light]].<ref>[http://medical-dictionary.thefreedictionary.com/photophobia thefreedictionary.com/photophobia] citing:
* Dorland's Medical Dictionary for Health Consumers. 2007
* The American Heritage Medical Dictionary Copyright 2007
* [[Miller-Keane Encyclopedia & Dictionary of Medicine, Nursing, and Allied Health]], Seventh Edition. 2003
* Millodot: Dictionary of Optometry and Visual Science, 7th edition. 2009</ref> 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,<ref>[http://medical-dictionary.thefreedictionary.com/photophobia thefreedictionary.com/photophobia] citing:
* Gale Encyclopedia of Medicine. Copyright 2008
* Mosby's Medical Dictionary, 8th edition. 2009
* McGraw-Hill Concise Dictionary of Modern Medicine. 2002</ref> though the term is sometimes additionally applied to abnormal or irrational [[fear]] of light, such as [[heliophobia]].<ref>[http://medical-dictionary.thefreedictionary.com/photophobia thefreedictionary.com/photophobia] citing:
* The American Heritage Medical Dictionary Copyright 2007
* Millodot: Dictionary of Optometry and Visual Science, 7th edition. 2009</ref> The term ''photophobia'' comes {{ety|el|''φῶς'' (phōs)|light||''φόβος'' (phóbos)|fear}}.<ref>[https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0057%3Aentry%3Dfw%3Ds2 φῶς], Henry George Liddell, Robert Scott, ''A Greek-English Lexicon'', on Perseus</ref><ref>[https://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0057%3Aentry%3Dfo%2Fbos φόβος], Henry George Liddell, Robert Scott, ''A Greek-English Lexicon'', on Perseus</ref>

==Causes==
Patients may develop photophobia as a result of several different medical conditions, related to the [[human eye|eye]], the [[nervous system]], genetic, or other causes.{{cn|date=October 2025}}

Photophobia may manifest itself in an increased response to light starting at any step in the [[visual system]], such as:{{cn|date=October 2025}}
* Too much light entering the eye. Too much light can enter the eye if it is damaged, such as with [[corneal abrasion]] and retinal damage, or if its pupil is unable to normally constrict (seen with damage to the [[oculomotor nerve]]).
* Due to [[albinism]], the lack of pigment in the colored part of the eyes (irises) makes them somewhat translucent. This means that the irises cannot completely block light from entering the eye.
* Overstimulation of the [[Photoreceptor cell|photoreceptor]]s in the [[retina]]
* Excessive electric impulses to the [[optic nerve]]
* Excessive response in the [[central nervous system]]

Common causes of photophobia include [[migraine headache]]s, [[TMJ]], [[cataract]]s, [[Sjögren syndrome]], mild traumatic brain injury ([[concussion|MTBI]]), or severe [[eye disease]]s such as [[uveitis]] or [[corneal abrasion]].<ref>{{cite journal |vauthors=Hazin R, Abuzetun JY, Daoud YJ, Abu-Khalaf MM |date=July 2009 |title=Ocular complications of cancer therapy: a primer for the ophthalmologist treating cancer patients |journal=Current Opinion in Ophthalmology |volume=20 |issue=4 |pages=308–317 |doi=10.1097/ICU.0b013e32832c9007 |pmid=19491683 |s2cid=205670593}}</ref> A more extensive list follows:

===Eye-related===
Causes of photophobia relating directly to the eye itself include:
{{div col|colwidth=20em}}
* [[Achromatopsia]]<ref>{{cite web |title=Achromotopsoa |url=http://www.ssc.education.ed.ac.uk/resources/vi&multi/eyeconds/Achro.html |access-date=December 11, 2009 |publisher=Scottish Sensory Centre}}</ref>
* [[Aniridia]]<ref name="taylor">{{cite book |last=Day |first=Susan |title=Paediatric Ophthalmology |date=January 15, 1997 |publisher=[[Wiley-Blackwell]] |isbn=978-0-86542-831-7 |editor=Taylor, David |edition=2nd |pages=1034–1036 |chapter=P9: Photophobia}}</ref>
* [[Anticholinergic]] drugs may cause photophobia by paralyzing the [[iris sphincter muscle]]{{Citation needed|date=February 2010}}
* [[Aphakia]]<ref name="tsbvi">{{cite web |title=Photophobia |url=http://www.tsbvi.edu/Education/anomalies/Photophobia.htm |url-status=dead |archive-url=https://web.archive.org/web/20090929192633/http://www.tsbvi.edu/Education/anomalies/Photophobia.htm |archive-date=September 29, 2009 |access-date=December 11, 2009 |publisher=[[Texas School for the Blind and Visually Impaired]]}}</ref>
* [[Blepharitis]]<ref>{{cite web |date=September 28, 2020 |title=Blepharitis |url=https://www.lecturio.com/concepts/blepharitis/ |access-date=July 5, 2021 |website=The Lecturio Medical Concept Library}}</ref>
* [[Buphthalmos]]<ref name="taylor" />
* [[Cataracts]]<ref name="taylor" />
* [[Coloboma]]{{Citation Needed|date=May 2025}}
* [[Cone dystrophy]]<ref name="taylor" />
* [[Congenital disorder|Congenital abnormalities]] of the eye<ref name="taylor" />
* [[Pinkeye|Viral conjunctivitis]]<ref>{{cite web |title=Conjunctivitis |url=http://www.merck.com/mmpe/sec09/ch101/ch101c.html |access-date=December 11, 2009 |publisher=[[Merck Manual of Diagnosis and Therapy]]}}</ref>
* [[Corneal abrasion]]<ref name="taylor" />
* [[Corneal dystrophy]]<ref name="taylor" />
* [[Corneal ulcer]]<ref>{{cite web |title=Corneal ulcer |url=http://www.merck.com/mmpe/sec09/ch102/ch102c.html |access-date=December 11, 2009 |publisher=[[Merck Manual of Diagnosis and Therapy]]}}</ref>
* Disruption of the [[corneal epithelium]], such as that caused by a corneal [[foreign body]] or [[keratitis]]<ref name="taylor" />
* [[Ectopia lentis]]<ref name="taylor" />
* [[Endophthalmitis]]<ref name="taylor" />
* Eye trauma caused by disease, injury, or infection such as [[chalazion]], [[episcleritis]], [[keratoconus]], or [[optic nerve hypoplasia]]<ref name="taylor" />
* [[Hydrophthalmos]], or congenital [[glaucoma]]<ref name="taylor" />
* [[Iritis]]<ref name="taylor" />
* [[Isotretinoin]] has been associated with photophobia<ref>{{Cite journal |last1=Fraunfelder |first1=F. T. |last2=Fraunfelder |first2=F. W. |last3=Edwards |first3=R. |date=September 1, 2001 |title=Ocular side effects possibly associated with isotretinoin usage |journal=American Journal of Ophthalmology |volume=132 |issue=3 |pages=299–305 |doi=10.1016/s0002-9394(01)01024-8 |issn=0002-9394 |pmid=11530040 |s2cid=37897437}}</ref>
* [[Optic neuritis]]<ref name="taylor" />
* [[Pigment dispersion syndrome]] {{Citation needed|date=February 2010}}
* [[Pupillary dilation]] (naturally or chemically induced)<ref name="tsbvi" />
* [[Retinal detachment]]
* [[Scar]]ring of the cornea or sclera<ref name="taylor" />
* [[Uveitis]]<ref name="taylor" />
{{div col end}}

===Nervous-system-related===
Neurological causes for photophobia include:
{{div col|colwidth=20em}}
* [[Autism spectrum]] disorder<ref>{{cite journal |vauthors=Fan X, Miles JH, Takahashi N, Yao G |date=November 2009 |title=Abnormal transient pupillary light reflex in individuals with autism spectrum disorders |journal=Journal of Autism and Developmental Disorders |volume=39 |issue=11 |pages=1499–1508 |doi=10.1007/s10803-009-0767-7 |pmid=19499319 |s2cid=32110116}}</ref>
* [[Chiari malformation]]
* [[Dyslexia]]<ref>{{cite web |title=Light sensitivity – photophobia |url=http://www.rnib.org.uk/EYEHEALTH/EYECONDITIONS/EYECONDITIONSDN/Pages/photophobia.aspx |access-date=December 11, 2009 |publisher=[[Royal National Institute of Blind People]]}}</ref>
* [[Encephalitis]],<ref name="taylor" /> including [[myalgic encephalomyelitis]]<ref>{{cite web |title=Chronic Fatigue Syndrome |url=http://www.healthsystem.virginia.edu/uvahealth/adult_infectious/cfs.cfm |access-date=December 11, 2009 |publisher=[[University of Virginia Health System]]}}</ref>
* [[Meningitis]]<ref name="taylor"/>
* [[Trigeminal]] disturbance causes [[central sensitization]] (hence, multiple other associated hypersensitivities). Causes can be bad bite, infected tooth, etc.<ref>{{cite journal |last1=Romero-Reyes |first1=Marcela |last2=Uyanik |first2=James M. |date=February 21, 2014 |title=Orofacial pain management: current perspectives |journal=Journal of Pain Research |volume=7 |pages=99–115 |doi=10.2147/JPR.S37593 |pmc=3937250 |pmid=24591846 |doi-access=free}}</ref>
* [[Progressive supranuclear palsy]], where photophobia can sometimes precede the clinical diagnosis by years<ref>{{cite journal |vauthors=Cooper AD, Josephs, KA |year=2009 |title=Photophobia, visual hallucinations, and REM sleep behavior disorder in progressive supranuclear palsy and corticobasal degeneration: a prospective study |journal=Parkinsonism & Related Disorders |volume=15 |issue=1 |pages=59–61 |doi=10.1016/j.parkreldis.2008.01.011 |pmid=18328771}}</ref>
* [[Subarachnoid haemorrhage]]<ref>{{cite web |title=Photophobia – Glossary Entry |url=http://ghr.nlm.nih.gov/glossary=photophobia |url-status=dead |archive-url=https://archive.today/20120719023419/http://ghr.nlm.nih.gov/glossary=photophobia |archive-date=July 19, 2012 |access-date=December 11, 2009 |work=Genetics Home Reference |publisher=[[United States National Library of Medicine]]}}</ref>
* [[Tumor]] of the [[posterior cranial fossa]]<ref name="taylor" />
* [[Visual snow]] along with many symptoms{{citation needed|date=July 2022}}{{div end}}

===Other causes===
{{div col|colwidth=20em}}
* [[Ankylosing spondylitis]]<ref>{{cite web |title=Ankylosing spondylitis |url=http://ghr.nlm.nih.gov/condition=ankylosingspondylitis |url-status=dead |archive-url=https://web.archive.org/web/20051109210225/http://ghr.nlm.nih.gov/condition=ankylosingspondylitis |archive-date=November 9, 2005 |access-date=December 11, 2009 |publisher=[[United States National Library of Medicine]]}}</ref>
* [[Albinism]]<ref>{{cite encyclopedia |title=Albinism |encyclopedia=MedicinePlus Medical Encyclopedia |publisher=[[United States National Library of Medicine]] |url=https://www.medlineplus.gov/ency/article/001479.htm |access-date=December 11, 2009}}</ref>
* [[Ariboflavinosis]]<ref>{{cite book |last1=Harris |first1=Robert S. |title=Vitamins & Hormones |last2=Thimann |first2=Kenneth V. |date=February 11, 1943 |publisher=[[Academic Press]] |isbn=978-0-12-709801-2 |volume=1 |page=88}}</ref>
* [[Benzodiazepines]]<ref>{{cite journal |vauthors=Wakakura M, Tsubouchi T, Inouye J |date=March 2004 |title=Etizolam and benzodiazepine induced blepharospasm |journal=Journal of Neurology, Neurosurgery, and Psychiatry |volume=75 |issue=3 |pages=506–507 |doi=10.1136/jnnp.2003.019869 |pmc=1738986 |pmid=14966178}}</ref><ref>{{cite journal |vauthors=Pelissolo A, Bisserbe JC |date=March–April 1994 |title=Dépendance aux benzodiazépines. Aspects cliniques et biologiques |trans-title=Dependence on benzodiazepines. Clinical and biological aspects |journal=Encephale |language=fr |volume=20 |issue=2 |pages=147–157 |pmid=7914165}}</ref>
* [[Chemotherapy]]<ref name="taylor" />
* [[Chikungunya]]<ref>{{cite journal |last1=Mahesh |first1=G. |last2=Giridhar |first2=A. |last3=Shedbele |first3=A. |last4=Kumar |first4=R. |last5=Saikumar |first5=S. J. |year=2009 |title=A case of bilateral presumed chikungunya neuroretinitis |journal=Indian Journal of Ophthalmology |volume=57 |issue=2 |pages=148–150 |doi=10.4103/0301-4738.45508 |pmc=2684432 |pmid=19237792 |doi-access=free}}</ref>
* [[Cystinosis]]<ref name="taylor" />
* [[Drug withdrawal]]
* [[Ehlers–Danlos syndrome]]
* [[Infectious mononucleosis]]<ref>{{cite journal |last1=Gauthier-Smith |first1=P. C. |date=December 22, 2004 |title=Neurological complications of glandular fever (infectious mononucleosis) |journal=[[Brain (journal)|Brain]] |publisher=[[Oxford University Press]] |volume=88 |issue=2 |pages=323–334 |doi=10.1093/brain/88.2.323 |pmid=5828906}}</ref>
* [[Influenza]]<ref>{{cite web |last=Hunt |first=Margaret |title=Influenza Virus (Orthomyxovirus) |url=http://pathmicro.med.sc.edu/mhunt/flu.htm |access-date=December 11, 2009 |publisher=[[University of South Carolina]] School of Medicine}}</ref>
* [[Magnesium deficiency (medicine)|Magnesium deficiency]]<ref name="durlach">{{cite book |last1=Durlach |first1=Jean |title=New Perspectives in Magnesium Research |last2=Morii |first2=Hirotoshi |last3=Nishizawa |first3=Yoshiki |date=March 6, 2007 |publisher=[[Springer Science+Business Media|Springer London]] |isbn=978-1-84628-388-8 |pages=117–126 |chapter=10: Clinical forms of Magnesium Depletion by Photosensitization and Treatment with [[Scototherapy]] |doi=10.1007/978-1-84628-483-0_10}}</ref>
* [[Mercury poisoning]]<ref>{{cite journal |author1=[[Centers for Disease Control and Prevention]] (CDC) |date=June 1990 |title=Elemental mercury poisoning in a household—Ohio, 1989 |url=https://www.cdc.gov/mmwr/preview/mmwrhtml/00001652.htm |journal=MMWR. Morbidity and Mortality Weekly Report |volume=39 |issue=25 |pages=424–5 |pmid=2113168}}</ref>
* [[Migraine]]<ref>{{cite journal |vauthors=Drummond PD |date=October 1986 |title=A quantitative assessment of photophobia in migraine and tension headache |journal=Headache |volume=26 |issue=9 |pages=465–469 |doi=10.1111/j.1526-4610.1986.hed2609465.x |pmid=3781834 |s2cid=10230356}}</ref>
* [[Mustard gas]] exposure
* [[Rabies]]<ref>{{cite journal |author1=Centers for Disease Control and Prevention (CDC) |date=October 28, 1994 |title=Human Rabies – Miami, 1994 |url=https://www.cdc.gov/rabies/publications/mmwr_4342.html |journal=[[Morbidity and Mortality Weekly Report]] |publisher=[[Centers for Disease Control and Prevention]] |volume=43 |issue=42 |pages=773–5 |pmid=7935313}}</ref>
* [[Tyrosinemia type II]]<ref name="taylor" />
* [[Superior canal dehiscence syndrome]]<ref>[http://www.scdssociety.com SCDS Society]</ref>{{nonspecific|date=December 2023}}
{{div end}}

==Treatment==
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.<ref>{{cite web |last=Bailey |first=Gretchyn |title=Photophobia (Light Sensitivity) |url=http://www.allaboutvision.com/conditions/lightsensitive.htm |access-date=November 13, 2012 |website=All About Vision}}</ref>

==Artificial light==
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 people 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 vision|peripheral]] light, precision tinted glasses, and/or wide-brimmed [[sun hat]]s 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.<ref>{{cite journal |author=Blackburn Marcus K. |display-authors=etal |year=2009 |title=FL-41 tint improves blink frequency, light sensitivity, and functional limitations in patients with benign essential blepharospasm |journal=Ophthalmology |volume=116 |issue=5 |pages=997–1001 |doi=10.1016/j.ophtha.2008.12.031 |pmc=2701948 |pmid=19410958}}</ref><ref>{{cite journal |last1=Katz |first1=Bradley J. |last2=Digre |first2=Kathleen B. |year=2016 |title=Diagnosis, pathophysiology, and treatment of photophobia |journal=Survey of Ophthalmology |volume=61 |issue=4 |pages=466–477 |doi=10.1016/j.survophthal.2016.02.001 |pmid=26875996}}</ref>

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.<ref>{{cite journal |vauthors=Stringham JM, Bovier ER, Wong JC, Hammond BR |year=2010 |title=The influence of dietary lutein and zeaxanthin on visual performance |journal=Journal of Food Science |volume=75 |issue=1 |pages=R24–9 |doi=10.1111/j.1750-3841.2009.01447.x |pmid=20492192 |doi-access=free}}</ref>

==Disability==
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.{{cn|date=October 2025}}

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 [[Light-emitting diode|LED (light-emitting diode)]] lamps.<ref>[https://www.axonoptics.com/photophobia-and-light-sensitivity/ Guide to Photophobia/Light Sensitivity], axonoptics.com. Retrieved January 11, 2019.</ref><ref>[http://www.lightmare.org/ Lightmare], lightmare.org. Retrieved January 11, 2019.</ref>

The increasing popularity of "overpoweringly intense" LED headlights being used on "[[Pickup truck|pickups]] and [[S.U.V.]]s" has prompted more frequent reports of photophobia among motorists, cyclists, and pedestrians.<ref>[https://www.nytimes.com/2021/06/05/business/led-hid-headlights-blinding.html "Blinded by Brighter Headlights? It's Not Your Imagination."], ''[[The New York Times]]'', June 5, 2021. Retrieved June 11, 2021.</ref>

==See also==
* [[Photic sneeze reflex]], a medical condition by which people exposed to bright light sneeze
* [[Photosensitivity in humans]]

==References==
{{reflist}}

== External links ==
{{Medical resources
| ICD10       = {{ICD10|H53.1}}
| ICD9        = {{ICD9|368.13}}
| MeshID      = D020795
| DiseasesDB  = 24599
| MedlinePlus = 003041
}}
{{Eye pathology|state=collapsed}}
{{Authority control}}

{{DEFAULTSORT:Photophobia}}
[[Category:Neurological disorders]]
[[Category:Phobias]]
[[Category:Visual disturbances and blindness]]