Darkness of tint is measured by Visible Light Transmission percentage (VLT%).
In New York State, this percentage refers to percentage of visible light allowed in through the combination of film and the window itself.
Front Side Windows - Must allow more than 70% of light in. Rear Side windows - Must allow more than 70% of light in. Front windshield - Must be 6 inches from the top
Back windshield - Any darkness can be used.
Medical Exemption - State allows medical exemptions for special tint. For more details about the specific terms of the exemption, consult your state law