Camera Lenses, one of the very special feature on Lumia 520. When you switch on the camera on this phone you could see some preloaded camera lenses like smart shoot. You can also download various lenses like panorama, face lens, Fhotoroom, Watercam etc from the store.
Each of these lenses has got their unique feature. For example, smart shoot will take multiple photos and lets you pick which one to save. You can select the best photo which has come well and this gets saved and the other photos are erased automatically.
FaceLens, is a funny app. When you switch on the camera and select this lense the face of the person you are trying to shoot gets morphed with an ape. When you try this lense you can see discover many features.