When you're driving, you want clarity, which is why it's important to have a clean windshield, back window, and rearview mirror. However, what happens when someone's lights are too bright at night? You may experience glare, which can cause Troxler Effect. This is a real condition that triggers temporary blindness. In fact, drivers can be blind for 2 seconds or more because of headlight glare in the rearview mirror due to this effect.