Brightness

Is it too bright? Don’t design in eye strain.

A display that’s too bright can cause eye strain, leading to discomfort and reduced productivity. While high brightness is great for signage and events, it can be harmful in workspaces where people need to focus for long periods.

How brightness affects the human eye

Our eyes work like cameras, constantly adjusting to different light levels. This requires muscular effort, and when brightness levels vary too much, it’s like forcing your eyes to do constant optical weightlifting. The result? Fatigue, discomfort, and lower efficiency.

This isn’t just theory—it’s backed by decades of research and industry standards from the Chartered Institute of Building Services Engineers (CIBSE), the Society for Light and Lighting, and the latest WELL V2 building standard.

The 3:1 Rule – Task Luminance Ratio (TLR)

There is universal agreement on a key metric: the Task Luminance Ratio (TLR), set at 3:1.

1. Balanced brightness across key objects – The brightest elements in a workspace (screens, paper, tables, people) should be no more than three times brighter than the darkest. This prevents excessive strain on the eyes.

2. Black levels matter more than white levels – If a display is too bright, white levels must be capped. This means contrast depends on deep, rich black levels, not just bright whites.

What does this mean for your displays?

For flat panel displays
Choose wisely. Watch out for glossy, reflective screens, as these create glare and unintended ‘cheap seats’ where visibility is poor.

For projection
The solution is ambient light rejecting (ALR) screens, and the industry leader is our – VDL Supernova. Its completely matt surface eliminates glare, delivering the best possible viewing experience.

Need help calculating the right brightness for a project?
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