Do you currently wear glasses or contact lenses?
I've just done what I always thought was impossible and passed the Class 1 eyesight requirements (inc the additional opthamlic assessment as I have a 3.0 dioptre astigmatism in one eye.)
Even if you lost vision in your poor eye, it's my understanding that you'd still be ok with "acquired monocularity" as long as you still get 6/6 in your good eye. See the CAA guidance notes for details, they're very detailed.