Lysfølsom

Ly​sfølsom is a Norwegian term describing sensitivity to light. It is used for several related phenomena, most commonly photophobia in the eyes and photosensitivity of the skin. The term can refer to normal variation in how people adapt to light, as well as medical conditions where light exposure provokes symptoms. It appears in clinical discussions, dermatology, neurology, and everyday language.

In the context of eye health, photophobia is a symptom rather than a disease. It can accompany migraines, meningitis, corneal irritation or inflammation, dry eye, or recent eye surgery. Refractive errors can also contribute. Certain medications may increase light sensitivity, including tetracyclines, isotretinoin, and some antipsychotics. People with photophobia often experience discomfort, pain, squinting, or tearing in bright environments.

Photosensitivity of the skin causes rash, redness, or blistering after sun exposure. Triggers include drugs such as tetracyclines, fluoroquinolones, sulfonamides, and nonsteroidal anti-inflammatory drugs, as well as metabolic disorders like porphyrias and hereditary conditions such as xeroderma pigmentosum. Management typically involves sun protection (protective clothing, broad-spectrum sunscreen, sunglasses), and addressing the underlying cause or avoiding triggering substances.

In other contexts, lysfølsom can describe materials or technologies that respond to light, such as photosensitive emulsions, polymers, or semiconductor components. The term emphasizes the capacity to react to light, whether in biological systems or engineered materials.