Naturally our eyes have the ability to adapt to a certain amount of light. Once our eyes are exposed to additional light from another source, then it causes discomfort. The discomfort imposed therefore reduces our visual performance. This additional light can be called glare. Glare can cause discomfort. Glare can be reflected from a shiny surface. Common examples of glare sources are; the sun, vehicle headlights spotted on oncoming traffic. Another example could be street light poles.
Simple ways of controlling glare can be from mounting blinds over windows, using Polaroid or lenses with anti-reflex coating. Additional screen guard covers (used on computers or cell phones) or simply re-positioning your seat indirectly to the light source can help to limit glare exposure.