"My eyes are happiest when"...it really depends...
To use an extreme example, back when I was experiencing corneal erosions (you don't want those), contrast itself was the enemy. You send me this website, I am going to have to play with my display settings and also probably put on sunglasses.
Thinking of more common contextual preference change, time of day comes to mind.
I wish my e-reader clients could pick up on my time-of-day settings changes, because sometimes I want contrast and white on black, just dimmed in general, and at other times I want sepia but brighter...but generally there are obvious rules that could be derived based on what time it is.
(Sending people to websites like this without caging it in some kind of wink or chuckle of an expression seems like it would be a bit over the top...)
To use an extreme example, back when I was experiencing corneal erosions (you don't want those), contrast itself was the enemy. You send me this website, I am going to have to play with my display settings and also probably put on sunglasses.
Thinking of more common contextual preference change, time of day comes to mind.
I wish my e-reader clients could pick up on my time-of-day settings changes, because sometimes I want contrast and white on black, just dimmed in general, and at other times I want sepia but brighter...but generally there are obvious rules that could be derived based on what time it is.
(Sending people to websites like this without caging it in some kind of wink or chuckle of an expression seems like it would be a bit over the top...)