Answer 6 questions to find out how much blue light you're absorbing from screens each day — and what it's doing to your sleep and eyes.
01
How many hours a day do you spend on your phone?
02
How many hours a day on a laptop or desktop screen?
03
What time do you typically stop looking at screens?
04
Do you use night mode or a blue light filter on your screens?
05
Do you wear blue light filtering glasses?
06
What's the lighting like when you use screens?
The daytime problem
Blue light affects your sleep, but during the day the bigger issue is blink rate. Screen use drops it by up to 70%, drying out your eyes long before evening. blink! tracks your blink rate in real time so you can address both halves of the problem.
The evidence for permanent retinal damage from typical screen blue light is weak at current exposure levels. Where blue light clearly does cause harm is sleep: it suppresses melatonin production, delaying sleep onset and reducing sleep quality — which in turn worsens eye fatigue and strain the following day. The cycle compounds quickly.
When does blue light matter most?
Evening exposure is the most impactful. The two hours before sleep are when melatonin production is most sensitive to disruption. Phone use in bed is the highest-risk behaviour — the screen is close to the face, the room is dark, and the content is typically stimulating. This combination significantly delays sleep onset.
Night mode vs blue light glasses
Both reduce blue light, but night mode (Night Shift / Night Light / f.lux) does so more consistently and at no cost. Blue light glasses vary significantly in quality and filtration level. If you can't avoid evening screen use, both together offer the most protection. During the day, neither addresses the core issue: reduced blink rate.