For the first few years here, working part-time, I was only marginally solvent, and that seemed like a chunk. So one night I got out the scissors, figured I'd watched people do it to me plenty of times, albeit in reverse, and gave it a go. You can too. Here are some self-tonsure tips.
Depth perception is a bit skewed.
They must've learned that in school, so go with it - it seems effective. A little bit here and there, trim those bangs in a line, wow, I can see again. This probably seems like a natural activity to do under the influence of alcohol or other non-prescription drugs, but I can't vouch for that myself. Call me chicken, but trying to control a blade near my head via mirror is quite enough for my brain to handle in a non-addled state. I'd prefer to skip the Van Gogh effect.