What is the best background light level to set on my phone or iPad?

Pros of higher light levels: As you raise the background light level the CONTRAST between dark typefaces and the generally lighter background increases. This is also true for lighter typeface on darker backgrounds. Higher contrast makes it easier to read, so brighter light settings are generally easier on the eyes. This is especially true in very bright environments — increase the background light level and you will increase the contrast.

Some people believe that you harm your eyes by setting the background light level too high. This is not true. The amount of light coming from computers or portable devices is not high enough to harm the eyes, even at the highest levels and for long periods of time.

The charge will last longer if you set the light level lower, but it might be harder to see, especially in bright situations. You might have less eye fatigue if you set your background light level a little higher.