Valonarkuus

Valonarkuus is the Finnish term for light sensitivity, a symptom defined by abnormal intolerance to light that causes discomfort or pain in bright environments. It is not merely a dislike of brightness but a perceptual or nociceptive response that can accompany ocular and neurological conditions.

Causes and associations: It commonly occurs with migraine, dry eye (keratoconjunctivitis sicca), corneal injury, uveitis, and conjunctivitis. It can also follow brain or cranial nerve injury and may appear with meningitis or other intracranial disorders.

Symptoms and assessment: People with valonarkuus may experience eye pain, tearing, burning, squinting, and headaches triggered by light. The severity depends on light intensity and wavelength. Clinicians take history and perform ocular examination; tests may include evaluation of pupil reactions and, in some cases, a light-discomfort threshold assessment.

Management: Treatment targets the underlying condition. Symptomatic measures include sunglasses with dark or photochromic lenses, hats with brims, reducing ambient lighting, and using artificial tears for dryness. In migraine, standard acute treatments and preventive strategies apply. Severe or persistent photophobia warrants specialist evaluation.

See also: Photophobia, light sensitivity, ocular pain.