I have Pinguecula and a brown pigment patch (nevi) in eyes - what is the best non-invasive treatment?

I am 39 years old and have had very dry and sore eyes every few days for about 3 years now. My recent check with the ophthalmologist confirmed I have Pinguecula (yellow and blood vessels) and brown pigment in my eyes (not malignant) but I would like to lighten those patches of yellow and brown. Is it true that there are drops that can lighten the brown pigment patch? And what is the best non-invasive treatment for the Pinguecula? Are there drops for that or is the only solution laser/surgery?