As eyes grow, their shape is determined by what they see. Viewing lots of black-on-white text (books, most web pages, etc.) moves the focal length one direction

As eyes grow, their shape is determined by what they see. Viewing lots of black-on-white text (books, most web pages, etc.) moves the focal length one direction. Viewing lots of white-on-black text would do the opposite, but that has gone out of style. That counts. I can't find the research right now, but I think it hit Hacker News a year or two ago.