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 Louisiana (LA), window tint laws are designed to ensure that visibility through vehicle windows is not excessively restricted. The state specifies the amount of visible light transmission (VLT) that must pass through the window tint on motor vehicles. Louisiana law requires a minimum VLT of 40% for the front side windows, 25% for the back side windows, and 12% for the rear window. The front windshield may have a non-reflective tint above the manufacturer's AS-1 line. The state also regulates the visual light reflection (VLR), allowing up to 20% reflection on the front side and back side windows. If a vehicle's window tint does not meet these requirements, the driver may receive a 'fix-it' ticket, which is a correctable violation. The driver must then correct the tint to comply with the law, pay a fine, and have the correction verified by an authorized person, such as a local police officer, to potentially have the ticket dismissed. Failure to correct the issue may result in a fine, additional tickets, and the violation being added to the driver's record. Non-compliance can also lead to a warrant for arrest if the driver fails to pay the fine or appear in court. Louisiana recognizes medical exemptions for drivers who require darker tints due to medical conditions and have documentation from a licensed medical professional.