Define light therapy.

• A. Light therapy is the production of beneficial effects on the body through treatments using rays or waves.
• B. Light therapy is a process of measuring light intensity for product safety.
• C. Light therapy is the use of bulbs to increase heating in the skin.
• D. Light therapy involves only infrared radiation therapy for pain.

Answer: (A)

Light therapy relies on using light exposure to trigger beneficial changes in the body through treatments that use specific rays or wavelengths. This means the therapeutic effect comes from the light itself—delivered in controlled doses and spectra to influence processes like mood, circadian rhythms, or skin cell activity. That’s why this definition fits best: it emphasizes the production of beneficial effects via light exposure.

The other ideas miss the core idea. Measuring light intensity is about assessment, not treatment. Relying on heating the skin is about heat therapy, not light therapy. Limiting to infrared radiation for pain narrows the concept incorrectly; light therapy can involve visible light as well as infrared, and targets a broader range of conditions beyond pain.