“Install the right type of peephole”
You never want to open a door unless you’re positive who’s on the next end. Generally, a peephole, peekhole, spyhole, doorhole or door viewer are often fitted with fish-eye lens, which will allow a wider field of view from the inside and little to no visibility from the outside. Often times entry doors are not equip from the manufactures with this devise, and those that have peepholes attached are sometimes so tiny that they don’t clearly show you who’s out there. Strangers can hide slightly out of view or appear so distorted, making it very difficult for you to identify.
Therefore, it’s very important to have a local contractor/handyman install the right peephole for you.