DaKrazedKyubizt
Regular
I only have one "good" eye. My right eye I need to have prescription glasses for, but my left eye was 20/20 last time I had it checked. My right eye is like 20/25 I believe, I can't quite remember. My point is that I feel like I haven't reached my full potential of F2L yet (granted I'm stil a 16-17s on average [full solve]), but I feel like my eye condition isn't the case. I do feel however if somebody had a more sever medical condition, this could certainly be the case, but my best guess is that on average it is not.
You guys should have some fun with this. Try solving with only one eye open. Try solving with only the other eye open. Make it fun, do a an average of 20 or something each, not just a few solves (I was going to suggest average of 50 but figured that'd be far too much).
Find a way to blur your vision, but be careful with that. You don't want to make your eyes work too hard to focus on something and end up screwing up your vision. Certainly don't go wearing prescription glasses that aren't prescribed for you. Maybe put some sort of translucent plastic between your face and the cubes.
Try solving in lower light conditions. This should force you to slow down.
Find more fun little things like this and test your outcomes. Whatever you do, do the same number of solves in each "test."
As for actually getting faster, learn to have spacial recognition on the fly (ie knowing what R U R' does to the ULB corner) and you'll notice a nice drop in F2L times. Slow down to the point that when you make the last move of your insertion, you can immediately know what move you are going to make next. Getting to this point is the hardest for me. I find that in some of my solves I can do this for pairs 2-4 (first pair is always different of how fast I approach it since I sometimes see the pair during inspection and/or cross building, sometimes don't). If I can consistently get to the point where I can make the final insertion move and immediately jump to my next pair, I'd drop a minimum of 2 seconds from my F2L.
Example:
Setup Alg:
R' U' R U2 R' U' R2 U' R'
If you did R U R' (normal insert here) you'll notice you can cancel that R' out into an R2, because R' U R will build your pair, then U2 and insert into back right slot.
Setup:
R' U R U R' U2 R2 U' R'
If you do the normal insert of R U R', if leaves R' U2 R U' to setup the back right pair + insert, (R' U' R), you can have that R' of the first pair insertion and that R' of the next pair cancel out into an R2.
Find more examples like these and you will certainly drop your times.
I'm certainly by no means a master (or even good) at F2L, but I've found that when my recognition of knowing what a corner will look like after I do some moves, my F2L time drops significantly.
I don't intend on this being any sort of hijack, but I just wanted to make clear what I valued as more important in the F2L recognition look ahead, which I really don't feel like vision therapy would help too much of, unless (as stated earlier) a medical condition actually hindered vision.
You're talking about eyesight. I'm not talking about eye sight. I can see just fine with my glasses on. I can solve a Rubik's Cube just fine without my glasses too. Yes, it's ridiculously blurry because my EYESIGHT is horrible, but my times are only slightly worse without my glasses, with or without squinting.
I'm talking about visual processing. Look it up. And look up how vision therapy is used to correct visual processing problems and why visual processing problems would arise in a human being.
EDIT: But yes, I'll try out what you've told me to try, with the bad lighting and whatnot.