Photophobia Definition: Medical Terminology Explained
What does photophobia mean? Understand the medical definition, pronunciation, ICD-10 codes, and the difference between photophobia and photosensitivity.
Medical Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider for diagnosis and treatment.
What Does Photophobia Mean?
Photophobia (pronounced: foh-toh-FOH-bee-uh) is a medical term derived from two Greek words:
- Photo (φωτός) — meaning “light”
- Phobia (φόβος) — meaning “fear”
Despite the literal translation “fear of light,” photophobia is not a psychological phobia. It is a neurological and ophthalmological symptom describing abnormal sensitivity or intolerance to light that causes discomfort or pain.
Medical Definition
In clinical practice, photophobia is defined as:
An abnormal sensitivity to light, especially of the eyes, characterized by discomfort or pain upon exposure to light levels that would not normally cause discomfort.
ICD-10 Code
The ICD-10-CM code for photophobia is H53.14 — “Visual discomfort, photophobia.” This code falls under:
- H53 — Visual disturbances
- H53.1 — Subjective visual disturbances
Healthcare providers use this code for billing and diagnostic documentation purposes.
Photophobia vs. Photosensitivity
These terms are frequently confused but refer to different conditions:
| Photophobia | Photosensitivity | |
|---|---|---|
| Affects | Eyes / nervous system | Skin |
| Response | Eye pain/discomfort from light | Skin rash, burn, or reaction from UV |
| Type | Neurological/ophthalmological symptom | Dermatological reaction |
| Common causes | Migraine, concussion, dry eye | Medications, lupus, sun allergy |
Some conditions like lupus can cause both photophobia and photosensitivity simultaneously.
Related Medical Terms
- Photosensitivity — abnormal skin reaction to sunlight
- Photodynia — pain caused by light (sometimes used interchangeably with photophobia)
- Photooculodynia — specifically eye pain from light
- Phonophobia — sensitivity to sound (often co-occurs with photophobia in migraines)
- Osmophobia — sensitivity to smell (also common in migraines)
Clinical Classification
Photophobia can be classified by origin:
- Ocular photophobia — originating from eye conditions (dry eye, uveitis, corneal damage)
- Neurological photophobia — originating from brain/nerve conditions (migraine, TBI, meningitis)
- Idiopathic photophobia — no identifiable underlying cause
How Photophobia Is Measured
There is no universally standardized test, but clinical assessments include:
- Utah Photophobia Symptom Impact Scale — patient-reported questionnaire
- Light sensitivity threshold testing — measuring the minimum light intensity that causes discomfort
- Pupillometry — measuring pupil response to light stimuli
Learn about photophobia symptoms →
Sources
- Digre KB, Brennan KC. “Shedding light on photophobia.” J Neuro-Ophthalmol. 2012;32(1):68-81.
- World Health Organization. ICD-10 Version: 2019. Code H53.14.
- Katz BJ, Digre KB. “Diagnosis, pathophysiology, and treatment of photophobia.” Survey of Ophthalmology. 2016.