The simplest answer is ensure lights are neither too bright nor too dim.

Use layered lights - ie not one single light source - which creates much better diffused lighting and generally better atmosphere.

There is actually a minsunderstanding about what causes eye strain. It is not too much brightness or dimness, but actually spending too long looking at one thing - so take breaks.

Ensure that task lights such as table lamps do not have direct light glaring into your eyes. Task lamps should be flexible with good shading.

Design lighting in the rooms you spend a long time in so that there are not too many shadows.

SOFTNESS is the answer - indoor lights should be diffused and generally soft.

One of the important things is that indoor lights should be warm white (3000K or so).

Use warm white in living rooms, but you can use harsher lights in bathrooms and kitchens.

Indoors always use diffuse globes rather than naked globes. This will go a long way to reducing or entirely eliminating eye strain.

There are guidelines as to how much light a room of a certain size, and function, should have - this should be followed.