What can easily damage Nikon SLR Lens?

I'm a paid photographer in the church where I worship. We're Four in our department. And I'm the most experience which gave me the opportunity to always buy our cameras {all Nikon products} For some time now we have been having problem with regards the Lens I bought. They always get bad before the period of warranty our supplier usually gave us [6 months]. And my colleagues always denied that they just get bad on it's own. And My supplier is saying that they got damage because of lack of proper care. So What could be the causes of the damages of our Lens?

Knocking lens around. Cleaning lens improperly, such as using liquid on them.

Are you saying that the lens is being shared by different people?

If so, misuse could well be the problem. And your supplier is correct. Improper care is the root cause of most lens and camera failure

I have lenses made in the early 1970's that still work just fine. I have a Nikon F2 and F4 that work perfectly fine as well.

It is VERY important that ANY SLR or dSLR cameras and their lenses be treated like the precision instruments they are.

NOTE:

Nikon gives standard 12 month warranties on cameras and a five year warranty on lenses. I find it interesting that your supplier "gives" you a 6 month warranty.

Hard knocks, trying to focus the lens manually when it's set to AF, setting it down on the rear surface without a cap, incorrect mounting and trying to force it…

The list is endless - ALWAYS cap your lens when not in use, NEVER swing the camera against a hard surface, NEVER attempt to focus manually, unless you've first set the selector to MF, ensure the lens is mounted correctly and don't let anyone else handle your camera.

Anyone dropping camera or lens should be barred from ever going near it again.

Sounds like people that don't know what they're doing with the equipment. Even a hammer can break with a fool using it.

I have a Nikkor 50mm 1.8 I bought in 1986 that still looks / works new. Nikon lens rarely go bad by themselves.
Always use them with clean hands. Store them in a padded case when not in use.

It sounds like misuse on the part of the other photographers. Dropping, storing in excessively cold temperatures and excessively hot temperatures, all take there toll. That's way I never put a camera in the glove compartment or the truck of my car. This = lack of proper care.

I must say being a "paid" photographer at a church is indeed a "coo" for you.

If you are having a rash of lens problems, you are probably not caring for it correctly. I own 9 Nikon lenses and have never had any problems with them.

And I often take them on vacation so the camera bag (with lenses inside) often gets shoved into an overhead compartment, trunk of a car (with a trunk full of luggage), and other semi-rough handling.

Someone with access to the lenses must really not be taking care of them.

How bad does it get? Scratches on the front lens element? Install a UV filter and don't take it off. The lens stops working altogether? I suggest for a week or so, observe how each of your co-workers use the camera and lens. You may be surprised on what you will discover with them unknowingly doing it.

It doesn't take much to take of a lens. In fact I don't do anything much except wipe the front end with lens paper if I happen to dab my fingers on it once in a while. Cleaning would be referred to a technician. Storage is in an air-tight food container with silica gel bags inside. It's all about proper use. All my lenses stay great even those that are decades old.