There are number of reasons you might want to keep the sun from shining through your windows. Perhaps you work at night and need a dark room so you can sleep during the day. Perhaps you live in a hot climate and want to keep your home cooler. Or maybe you want to block harmful ultraviolet rays. There are a few different ways of keeping the sun out. Some are more effective than others, but all are fairly simple to do.
Shut the blinds or pull down the shades. This is the easiest way of keeping the sun from shining through your windows. To close the blinds, you usually pull a drawstring or twist a rod hanging from the blinds.
Apply sunblocking film to the glass panes of your windows. The film adheres to your window like a sticker, creating a tinted window. Be careful and patient when applying the film to avoid trapped air bubbles.
Use blackout shades or curtains. These are heavy shades or curtains designed to block the sunlight from coming through your windows. Blackout curtains are more effective than the other methods; they block the sunlight almost entirely.