Are light backgrounds really easier to read for people over 45?
While it may seem that this question has been discussed to death, I find one aspect missing in previous discussions of black-on-white vs. white-on-black for text display.
The effect of age on the eye's accommodative ability, i.e. the loss of focussing range that comes with age means that it becomes easier to read black-on-white text when you grow older, just because it's easier to focus on.
After an older relative mentioned this to me, I found it pretty obvious that a smaller opening in the eye's pupil will provide a larger depth of field than a larger pupil.
It seems to be so obvious that it is rarely mentioned but here is a chapter from a textbook that does mention it: https://www.colorado.edu/physics/phys1230/phys1230_fa01/topic36.html
... the increase in f/number as the ambient light increases is important in increasing the depth of field of the optical system, and it is one of the reasons that it is easier to read and do other tasks that require precise focusing when the light is brighter.
I am observing in myself that I find black-on-white easier to focus and I am wondering why this is never mentioned in the relevant discussions on here.
In none of the other questions about this is ever age mentioned as a factor:
- Dark on Light or Light on Dark?
- What are the negative and positive aspects of dark color scheme?
- Dark or white color theme is better for the eyes?
Even the discussion in Do UI adjustments for people 45+ harm younger user UX? does not mention this.
Am I just imagining this? Or do other people experience this too?
Is this a good enough reason to suggest starting new designs with a light theme?