Replace Iphone 4 Camera Lens

camera lens
A camera lens (also known as photographic lens, objective lens or photographic objective) is an optical lens or assembly of lenses used in conjunction with a camera body and mechanism to make images of objects either on photographic film or on other media capable of storing an image chemically
an arrangement of circular concave or convex pieces of glass that control incoming light rays by focusing them on a ground glass or photosensitive film.
a lens that focuses the image in a camera

iphone 4
The iPhone 4 is a slate smartphone designed and developed by Apple. It is the fourth generation of iPhone, and successor to the iPhone 3GS.

replace
supplant: take the place or move into the position of; "Smith replaced Miller as CEO after Miller left"; "the computer has supplanted the slide rule"; "Mary replaced Susan as the team's captain and the highest-ranked player in the school"
Provide or find a substitute for (something that is broken, old, or inoperative)
Take the place of
put something back where it belongs; "replace the book on the shelf after you have finished reading it"; "please put the clean dishes back in the cabinet when you have washed them"
Fill the role of (someone or something) with a substitute
substitute a person or thing for (another that is broken or inefficient or lost or no longer working or yielding what is expected); "He replaced the old razor blade"; "We need to replace the secretary that left a month ago"; "the insurance will replace the lost income"; "This antique vase can