Well first this comes from one of the FAQ's " Usually, a snake will rub them off himself eventually, but if not, it will not hurt the snake for them to wait for the next shed. "

Come on. Really? How would you feel if you had pink eye, sun glasses or eye patches on ALL the time. It's common sense and visually obvious they are NOT meant to be there.

To answer your question. My usual ambient humidity is between 50% to 60 something percent. Once I see the milky eyes I up it to 705 to 80%. Also I integrated a Zoo Med Repti Fogger system and hydrostat into my setup (I forgot to mention this) after the first shed and it worked wonders on everything but the head and eyes.

But to answer your question stuck caps can and do cause serious problems as well as reducing the snakes quality of life.