Blue Light Blocking Glasses

Key points

• Blue wavelength light (480nm) suppresses melatonin via ipRGCs — specialised retinal cells that signal the suprachiasmatic nucleus
• Even dim overhead light after 10pm is enough to delay melatonin onset by 1–2 hours in sensitive individuals
• Blue blockers are a compensatory tool — dim warm lighting is more effective if achievable
• Wear after 9pm with any screen use; remove when going to bed — the goal is melatonin onset, not light blocking during sleep
• Red/orange tinted lenses (not clear "computer glasses") are required — clear lenses do not block the relevant wavelengths