Light Therapy

Definition

Light therapy is a treatment that uses exposure to daylight or to specific wavelengths of light using various devices to treat certain medical conditions, often related to sleep issues and mood disorders.

Scientific / Technical Definition

Light therapy, also known as phototherapy, involves exposure to artificial light that mimics natural sunlight. It is primarily used to treat Seasonal Affective Disorder (SAD), other types of depression, and circadian rhythm sleep disorders. The therapy comes in the form of light boxes, lamps, or other devices that emit bright light, usually at an intensity of 10,000 lux, which is significantly brighter than regular indoor lighting.

Benefits

• Regulates sleep-wake cycles.
• Improves mood and alleviates symptoms of depression.
• Increases alertness and cognitive performance.
• Helps adapt to a new time zone during travel.

Examples

• Using a light therapy box for 20-30 minutes each morning.
• Installing daylight-spectrum lighting in workplaces or homes.
• Using dawn simulators to gradually increase light in the bedroom.

Additional Information

• Side effects: Potential side effects include eyestrain, headache, nausea, and irritability. These are generally mild and resolve with time.

Related Terms

• Circadian Rhythm
• Melatonin
• Sleep Hygiene

References

• Light therapy in psychiatric care: an overview of its mechanisms of action and clinical applications (Nussbaumer-Streit et al., 2019)
• American Psychiatric Association: Seasonal Affective Disorder