Patients may develop photophobia as a result of several different medical conditions, related to the eye, the nervous system, genetic, or other causes. Photophobia may manifest itself in an increased response to light starting at any step in the visual system, such as: *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(s) 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 can't completely block light from entering the eye. *Overstimulation of the photoreceptors in the retina *Excessive electric impulses to the optic nerve *Excessive response in the central nervous system Common causes of photophobia include migraine headaches, TMJ, cataracts, Sjögren syndrome, mild traumatic brain injury (MTBI), or severe ophthalmologic diseases such as uveitis or corneal abrasion. A more extensive list follows: Eye-related Causes of photophobia relating directly to the eye itself include: * Achromatopsia * Aniridia * Anticholinergic drugs may cause photophobia by paralyzing the iris sphincter muscle. * Aphakia * Blepharitis * Buphthalmos * Cataracts * Coloboma * Cone dystrophy * Congenital abnormalities of the eye * Viral conjunctivitis * Corneal abrasion * Corneal dystrophy * Corneal ulcer * Disruption of the corneal epithelium, such as that caused by a corneal foreign body or keratitis * Ectopia lentis * Endophthalmitis * Eye trauma caused by disease, injury, or infection such as chalazion, episcleritis, keratoconus, or optic nerve hypoplasia * Hydrophthalmos, or congenital glaucoma * Iritis * Isotretinoin has been associated with photophobia * Optic neuritis * Pigment dispersion syndrome * Pupillary dilation (naturally or chemically induced) * Retinal detachment * Scarring of the cornea or sclera * Uveitis Nervous-system-related Neurological causes for photophobia include: * Autism spectrum disorders * Chiari malformation * Dyslexia * Encephalitis including myalgic encephalomyelitis * Meningitis *Trigeminal disturbance causes central sensitization (hence, multiple other associated hypersensitivities). Causes can be bad bite, infected tooth, etc. * Progressive supranuclear palsy, where photophobia can sometimes precede the clinical diagnosis by years * Subarachnoid haemorrhage * Tumor of the posterior cranial fossa * Visual snow along with many symptoms. Other causes * Ankylosing spondylitis * Albinism * Ariboflavinosis * Benzodiazepines * Chemotherapy * Chikungunya * Cystinosis * Drug withdrawal * Ehlers–Danlos syndrome * Infectious mononucleosis * Influenza *Magnesium deficiency * Mercury poisoning * Migraine * Rabies * Tyrosinemia type II * Superior canal dehiscence syndrome
symptom of Scleritis
symptom of Vasculitis
symptom of Lupus nephritis
symptom of Glaucoma
symptom of Otitis media
symptom of Avascular necrosis
symptom of Reye syndrome
symptom of Giant cell arteritis