Rearview mirrors are continuing to evolve with regard to dimming capabilities, according to the Wall Street Journal. Gentex Corp. manufactures rearview mirrors with automatic dimming capabilities.

The mirrors are equipped with sensors that calculate the amount of light entering the vehicle from all directions, according to the report. The sensors trigger an electrically sensitive gel that darkens the mirror to reduce glare.

The technology is currently available in optional packages for all Volvo vehicles, though the article indicates that it comes standard on high-end vehicles. Among those that are standard equipped with the technology are the Toyota Avalon XLS Limited (on both side mirrors), the Sienna Limited (driver's side only), the Cadillac STS (exterior driver's side only) and the Cadillac Escalade (all three mirrors).

The anti-glare mirror system can be installed in older vehicles, the article added, though it can be harder to add if the vehicle doesn't have proper wiring. Auto-dimming side mirrors can only be added if an anti-glare rearview mirror system is already in place.

The automatic anti-glare mirrors can also be equipped with a digital compass, an outside temperature display and a garage door opener system.