I spent about $3000 in total on dental (cleaning and perio-scaling, not surgery), eyeglasses and after-tax insurance payments. Are any of these adjustable? (since this is less than the $3400 standard deduction, I would like to not itemize. I'm filing 1040NR).

You can deduct only the amount of your medical and dental expenses that is more than 7.5% of your adjusted gross income (Form 1040, line 38). That is you must subtract 7.5% (.075) of your adjusted gross income from your medical expenses to figure your medical expense deduction. Then it is deductible only if you itemize your deductions.

You will not itemize unless your itemize deductions are more than your standard deductions.