Why can age change the starting point for lighting?
July 26, 2026 · Updated October 29, 2026 · 2 min read · Harlowelife research and product team
The key point
The eye's optical conditions change during adulthood. Changes in lens transmission and pupil size can mean that the same room light produces different retinal stimulation.
Age can inform a starting recommendation, while a person's stable preferences should remain able to refine it.
The same lamp does not mean the same retinal exposure
Research has examined how age-related changes in lens transmission and pupil size affect light reaching the retina. This supports treating age as useful context rather than assuming one default for everyone.
It does not support a simple rule of maximum brightness for older users. Recommendations should remain adjustable, visible, pausable and resettable.
Evidence boundary
Age is not a diagnosis or an automatic reason to increase brightness. Glare sensitivity, eye conditions, medicines and personal preferences require separate consideration.