@Droopy I can appreciate your concern, and share them to some extent- I will definitely be needing cataract surgery myself in the future.
You can see very little though. You will be given eye drops to dilate the pupil, and that point pretty much everything happening around the eye will just become a shadow.
I have included a link to a page outlining the process of the surgery itself, which may help calm the nerves a bit - generally, the more you know, the more relaxed you can be about the process.
http://www.nhs.uk/Conditions/Cataract-surgery/Pages/How-it-is-performed.aspx
My Father has recently had cataracts removed, and he says he saw nothing of the scalpel or anything like that....