How do you edit the restrictions on your learner's permit?

I have my learner's permit and one of the restrictions is 'B' for corrective lenses. However, I passed my eye test when I got my permit, and I don't have glasses. How would I change that restriction? I tried calling the RMV (Massachusetts) but none of the categories seemed correct. What do I do to change this restriction so it doesn't say that I need glasses?