All states have traffic laws that limit the amount of window tint on motor vehicles—often by specifying the amount of visible light transmission (VLT) that is required. VLT is the amount of light that is transmitted through the window and into the vehicle. For example, a 70%VLT means that 70% of light will pass through the window and 30% will be reflected. Thus, a lower VLT indicates a darker film or tint.

Another term to know is visual light reflection (VLR)—which is the opposite of VLT. VLR is the amount of solar energy that is reflected off the glass and away from the inside of the vehicle.

In most states tickets or citations for illegal window tint are known as fix-it tickets and the ticket or citation will indicate that it is a correctable violation of traffic laws. For example, if you fix the window tint problem within the required period, pay a small fine, and get the signature of an authorized person (a local police officer) the court may dismiss the ticket.

But if you fail to fix the window tint problem within the required period you must pay the fine for the violation and you may be issued another ticket that will be part of your driving record. And if you fail to pay the ticket or appear in court on the hearing date the court may issue a warrant for your arrest.

Window tint laws vary from state to state and some states have exemptions for certain vehicles such as limousines and recognize medical exemptions when the driver has a written statement from a licensed medical doctor, ophthalmologist, or optometrist.

In Indiana, window tint laws are regulated under Indiana Code Title 9. Motor Vehicles § 9-19-19-4, which specifies the allowed levels of window tint on vehicles to ensure safety and visibility. The law mandates that the front side windows must allow at least 30% of the light to pass through (70% VLT), while the back side and rear windows can be tinted to any darkness. The windshield may only have a non-reflective tint applied to the top equivalent to the manufacturer's AS-1 line. Indiana does not have a specification for VLR (visual light reflection), but the window tint must not be more than 25% reflective. Medical exemptions are available for individuals who require a darker tint due to medical conditions, and they must carry documentation from a licensed physician. Violations of the window tint laws can result in a 'fix-it ticket,' which is a correctable violation. If corrected within the specified period and verified by an authorized person, such as a local police officer, the court may dismiss the ticket. Failure to correct the issue or to pay the fine can lead to additional tickets and potentially a warrant for arrest if court appearances are missed.