You should just go down slowly and carefully because it may crush the lens. Thats all of my advice to all of you amazing viewers out there. <3 J-DAWG
The outward curving of the lens is said to be a convex lens.
A lens that is thinner in the middle and thicker at the edges is called a concave lens.
There is none
Place a small amount of lens-cleaning fluid on a clean sheet of lens paper. Make one small circular pass on the lens and toss out. If lens is still dirty - repeat.
To provide a wide angle of view out.
Peep hole
A hole to peep through.
a peep hole, such as you'd find in the door of a hotel room, uses a concave lens to make the image of the person standing in the hallway appear smaller than they actually are.Glasses for nearsighted people.
bebo maybe?
A circular piece of metal with a hole in it.
peep
peep
peep
peep
peep
wheelchair user needs a peep-site 3'6" off the floor.