A peep hole is the best way to see through a front door without opening it. A dirty peep-hole blocks your view, and might be detrimental to your safety. Keeping a peep hole clean aids in keeping your home safe and secure.
Clean the interior side of the peep hole with a cotton swab soaked in glass cleaner.
Clean the exterior side of the peep hole; use glass cleaner and a paper towel.
Look through the peep hole to verify that there are no streaks or moisture on the lenses. Use more glass cleaner -- on a cotton swab or paper towel -- if streaks are evident. Use the low-heat setting on a hair dryer to eliminate moisture.