Migraine: This is often the most common cause of light sensitivity, as migraines can be triggered or exacerbated by bright lights, leading to photophobia. The condition is relatively prevalent and can significantly impact an individual's quality of life.

Dry Eye Syndrome: This condition can cause discomfort and sensitivity to light due to the lack of sufficient lubrication on the surface of the eye. It's a common issue that can be exacerbated by environmental factors, prolonged screen time, or certain medications.
Conjunctivitis: Whether viral, bacterial, or allergic, conjunctivitis (pink eye) can cause light sensitivity along with redness, itching, and discharge. It's a common condition that can affect anyone.
Uveitis: Inflammation of the uvea, the middle layer of the eye, can lead to light sensitivity, along with eye pain and vision problems. It can be associated with various systemic diseases or occur independently.

Acute Angle-Closure Glaucoma: A medical emergency that can cause severe eye pain, blurred vision, and significant light sensitivity. Missing this diagnosis can lead to permanent vision loss, making prompt recognition and treatment crucial.
Meningitis: Inflammation of the protective membranes covering the brain and spinal cord can cause photophobia, along with fever, headache, and stiff neck. It's a potentially life-threatening condition that requires immediate medical attention.
Subarachnoid Hemorrhage: Bleeding into the space between the brain and the tissue that covers it can lead to sudden, severe headache, photophobia, and sometimes loss of consciousness. It's a critical condition that necessitates urgent medical intervention.

Albinism: A group of rare genetic disorders that affect the production of melanin, leading to vision problems, including sensitivity to light. Individuals with albinism often have other distinguishing features, such as pale skin and hair.
Photorefractive Keratectomy (PRK) Complications: After PRK surgery, some patients may experience light sensitivity as a complication. This is less common but can be a significant issue for those affected.
Sjögren's Syndrome: An autoimmune disorder that primarily affects the glands that produce tears and saliva, leading to dry eyes and potentially light sensitivity among other symptoms. It's less common than other causes of photophobia but should be considered in patients with systemic autoimmune symptoms.