Specs deduction
I have a degree in Accounting and did my own taxes for thirty years, including all the years I was in aviation.
Having said that, the test might be if you would otherwise need your glasses for ordinary activities of life. That may well be a gray area. In my case, I wore glasses before I started flying and switched to contacts with a SODA directing that I carry "an extra set of corrective lenses during all times that was exercising the privileges of [my] airman certificate." So, could I deduct my extra set of glasses? I don't think so, because I needed corrective lenses anyway.
You might be able to deduct your glasses as a medical expense. However, you cannot deduct anything as a medical expense unless your cumulative deductions are at least something like 7% of your adjusted gross income.
Hope this helps a little more. I second the suggestion about reviewing the IRS pub on deductions.