The eyesight standards did indeed change a few years back...I believe 6/12 is now the minimum visual acuity to be achieved in each eye, correctable to 6/6. If you're worried about your eyesight deteriorating (which I'm afraid to say is a huge problem among university students) why don't you consider applying direct entry if the RAF is definitely what you want to do?
Just remember that grades aren't everything to the RAF...not to say that they won't be an extra string to your bow, but try to remember they place a lot of emphasis on spirit of adventure, community contribution, physical robustness, confidence in leadership and proof that you've worked in a team.
The best people to speak to regarding anything medical are the OASC medical staff...the AFCOs take decades to be brought up to speed...I remember when I first applied, I had to correct them on a handful of parameters for entry as aircrew.
All the best, and good luck!!
