A camera stream that is blurry, fuzzy or out of focus can usually be resolved quickly.
If video stream is choppy or pixelated (blocky), please see How to: Improve Poor Video Quality.
What Causes Blurry Video
Physical obstructions
Look for any of the following physical obstructions:
Dirt, grease, and grime
Glue or gummy residues (ie post-it or sticker residue)
Moisture inside or outside the lens (see Damage)
Your camera lens should only be cleaned according to the manufacturer's instructions. Avoid scratching the lens at all costs when cleaning.
Out of focus camera lens
If your camera has zooming functionality, Refer to that device's user manual to adjust the focus of your camera.
Damage
A camera can receive damage from a hard fall or impact. The lens can become permanently out of focus, requiring the camera to be replaced.
Likewise, exposure to excessive moisture can cause water to get inside of the lens, creating a blur. Typically moisture is very difficult to remove