1. Form HSMV 83390, Application for Sunscreening Medical Exemption, accurately completed. Obtain a signed statement from a licensed physician validating the need for darker window tints.How to get a medical exemption for window tint. In most cases, you will need to fill out a vehicle tint-waiver request form — or some form along those lines — depending on where you reside. Go to your state and fill out an affidavit form for a medical exemption.