Hi. I Became A Vegetarian (for Moral And Ethical Reasons)

Hi. I became a vegetarian (for moral and ethical reasons) last month, but I have noticed significant health benefits to this change of well... life, for want of a better word. My eyes, which were fairly bad -3 in each one seem to have improved. My progressive contact lens seem too strong for me now. Is this even possible?
I have had the same prescription for at least 6 years and it has always been fine, no problems at all so the fact that over the course of a month this has happened has got me curious.
Thank you.
Lori