They are broad band IR filters because those are easier to design. Apple is likely using a very narrow band that doesn't have sun problems (see IR window from 8

They are broad band IR filters because those are easier to design. Apple is likely using a very narrow band that doesn't have sun problems (see IR window from 8-14nm). https://en.m.wikipedia.org/wiki/Infrared_window https://en.m.wikipedia.org/wiki/Infrared_window However that nice band also gets filtered by polycarbonate which is common in sun and protective glasses. It also gets heavily cut by other typical IR absorbers, and creating a pass window will cost more money.