Pianists call real-time reading "sight-reading", and it's not what pianists usually focus on. Even the most skilled pianist is probably not going to sight-read

Pianists call real-time reading "sight-reading", and it's not what pianists usually focus on. Even the most skilled pianist is probably not going to sight-read a Bach fugue (or be satisfied with the result). The more common way to read music (at least in terms of the large and marvelous classical piano literature), is as part of a careful process of studying. You read to learn and understand the music, but the reading doesn't need to be real-time (it normally isn't, when learning a piece). Real-time sight-reading is its own special skill, which you can practice for its own sake. But it's nowhere near as important as the non-real-time learning process mentioned above. I got pretty good at sight-reading when I worked as an accompanist, but I still hate it: It's not how I like to learn a piece. (And the music I find most interesting [like Bach!] can't even really be learned that way).