It used to be that you could have one eye if you'd already got your licence, but that was years ago. The main thing is to find out what's happening to your eye.
These days you should be able to find out exactly what the problem is. If it's to do with the lens, then it's significant to mention that I've had good eyesight for years after both lenses were changed following vitrectomy. When I say good, I mean starting at the bottom line. I was in my 60's when this all started.
I had the vitrectomy operations about ten years apart because of floaters. The last one, with a 'peel' was with local anaesthetic.
I was not happy with the edge of the second lens and finally had a laser procedure with a lovely lady who did about ten zapps to tidy things up. It was an instant improvement. They use this to clear the lens encapsulation in older folk.
The point being, they can do one heck of a lot these days. Having got as far as you have, put work into researching just what can be done. My pal had lenses done when he finished flying and is enjoying the best eyesight he's ever had.