Aside from Disrupting Melatonin, What Are the Other Effects of Blue Light?

Blue light, particularly in the short-wavelength and high-energy range (typically 415–455 nm), is emitted by screens, LED lighting, and other digital devices. While some blue light exposure during the day is natural and even beneficial, excessive or nighttime exposure can negatively impact both visual and systemic health.

Visual Strain & Discomfort

Blue light scatters more easily than other visible wavelengths, making it harder for the eye to focus. This results in unfocused "visual noise," which reduces contrast and may cause:

• Digital eye strain (also known as Computer Vision Syndrome)

• Dry or irritated eyes

• Blurred vision

• Headaches or difficulty focusing

Sleep Disruption

Blue light in the evening suppresses melatonin production — a hormone critical to sleep-wake regulation. Even short-term exposure before bed can delay sleep onset, reduce sleep quality, and disrupt natural circadian rhythms.

Potential Long-Term Health Risks

Emerging research suggests that prolonged exposure to artificial blue light at night may increase the risk of:

• Hormone-related cancers (e.g., breast and prostate)

• Type 2 diabetes

• Cardiovascular disease

• Obesity

• Mood disorders

• Age-related macular degeneration (AMD)

While further research is ongoing, many scientists advise limiting exposure to artificial blue light in the evening to support better health outcomes.