I'm in the process of applying for the NSWPF, I have completed the PEE (entrance exam) and about to finish off the UCWE. If you have any questions feel free to slide in my dms.
In terms of eye sight, when you are called in for a general medical you are tested and scored on two things, 1) without glasses (uncorrected vision) and 2) with glasses (corrected vision). You need to meet the minimum score for uncorrected vision, I can't remember off the top of my head what that score is but basically you can't be as blind as a bat.
If you need to wear glasses you will have to go to an optometrist for further evaluation, this is done in addition to the general medical. If you decide to get glasses make sure the lenses are made from polycarbonate material, they're practically bullet proof and is a must according to NSWPF policy.
TV shows like beach cops and highway patrol incorrectly depicts what real policing is, make sure you talk to police officers before pursuing a career in policing.