Staring at phone and computer screens exposes your eyes to harmful blue light that permanently damages your vision.
Blue light (400–500 nm) from displays reaches the retina and can trigger fatigue in the ciliary muscle and disruption of melatonin (impacting sleep), but does not damage photoreceptor cells or cause macular degeneration. Clinical studies on screen use find no evidence of permanent photochemical injury from device-emitted blue light at normal viewing distances; outdoor sunlight contains 10–100 times more blue light, and we evolved under unfiltered solar exposure. Digital eye strain (dry eyes, focusing fatigue) reflects accommodative demand and reduced blink rate, solved by 20-20-20 breaks, not blue light filtering. The 'blue light blocking' eyewear and screen filters market erupted post-2015 as a marketing response to sleep disruption concerns, with minimal clinical validation for visual health. Legitimate concerns include sleep disruption (evening screen use suppresses melatonin) and myopia progression (possibly linked to reduced outdoor time, not blue light directly), both addressable through behavioural change. The permanent damage narrative is marketing-driven; screens cause fatigue and may affect sleep, not blindness.