Welcome to Fluther.

I am not an optometrist, but I think it’s plain that you need to get the prescription as written by your doctor. I wouldn’t make any substitutions at all.

It probably won’t hurt (the difference is something like ¼ of a millimeter. Your eye will compensate.

However, there is one additional number you will need – the PD – Pupillary distance – basically the number of millimeters between the pupils of each eye. If you don’t have that, you will run a serious risk of getting glasses that don’t work.

By the way, I just bought an online pair from Zenni Optical – it came in about 8 days, perfect and to spec. And cheap. $39 for a pair that would have been $129 (at least) at lenscrafters.

I’m not an eye doctor either, but you have a fair amount of astigmatism along with moderate near-sightedness. The quarter-diopter error probably won’t matter, but you won’t have your sharpest vision. I’d spend a little extra for a good optician (online okay, I guess) who can properly fill the prescription.

Honestly, I’ve been wearing glasses since I was ten years old, and am currently cycling through several old pairs since I haven’t been able to afford new ones in some time. I can totally tell the difference between my newest pair (-3.50R, -3.75L) and my next older pair (-3.50 both eyes).

It’s not really noticeable, but my eyes get tired really quickly with the older pair.