What do you suggest if my left eye contact lens feels uncomfortable, but my right one doesn't. any ideas on why this would be?

Contact lens: An uncomfortable contact lens can be due to: old CL, dry eye, foreign body, early contact lens overwear, superficial punctate keratitis, infection (bacterial or viral), ulcer. Take out, try not to use for a day: if pain persists with it out, see eyeMD asap. Can try a new CL in that eye using lid hygiene (see eyedoc2020.blogspot.com) and nonpreserved tears: if pain returns see eyeMD asap.