Examples of secondary lenses designed to be used in front of the primary lens are:

Most photographic lenses designed for film cameras cannot be adapted to work on 3-chip video cameras.

The condenser is a lens designed to focus light from the illumination source onto the sample.

You have a lens designed to teach people what they need to know to confidently sign up for your tour.

The type of lens being designed is significant in setting the key parameters.

This is why each manufacturer offers a range of lenses designed for its format.

It is a "pancake" lens, a very compact prime lens designed to be easily portable.

The lenses made for extended wear, which became available in 1981, are marketed as more convenient alternatives to lenses designed to be taken out daily.

Almost all lenses designed for the Four Thirds system are of this type, as telecentricity is a stated design goal.

This brings the battery of lenses designed for the camera to an even dozen.