I asked this serious question a while ago and only got silly answers. How do blind people know when they have used enough toilet paper? It is not the sort of question I could ask a blind person (I don't know any). Brawburd asked if i could not use the toilet in the dark, and the answer is no, i couldn't. Sometimes I use several sheets, sometimes only a few, it all depends.
well it is a wee bit of a silly question. trying to formulate a serious answer: having no sight means you tend to rely on the other 4 senses considerably more than an able-sighted person would. without going into too much detail you can tell the difference between a clean bum and a dirty one by touch through the paper. i know this cos i don't like inspecting my last meal myself and use this method though i can see perfectly well thankyou. bear in mind that in some countries, toilet paper isn't used and use of your hand and some soap and water is all that is required. quite more hygienic really if you ask me, than smearing it all over the bum anyway i digress so does this answer your question?
I don't think it is a silly question at all, just embarrassing. I rely on sight absolutely when using paper. I think smell woould lead you to keep wiping indefinitely and would not be at all pleasant. Touch would probably lead me to stopping too soon. I conclude that it is a waste of time asking this question on Answerbank, since it is almost impossible for a blind person to use the web, I am not likely to get a sensible or correct answer.
Windows caters very well for the blind; text to speech is easy. As for bumwiping, try synaesthesia; Ever close your eyes when your working on something complex like untying a knot? well it's similar. - Good Grief.
I'm not really sure why it concerns you, but you're quite right that there would be difficulties. My main worry would be the beginning and end of menstruation.