1.   First, insects have compound eyes consisting of up to several thousand optical units called ommatidia, each with a single lens.

2.   Many animals have a single lens used to focus light on to a plate able to convert it into nerve impulses.

3.   The balancing treatment is also used to reduce the colour effects which a single lens would produce because of the dispersion of the glass.

4.   Collins said he sees the issue through a single lens.

5.   Nikon and Canon Inc. are among the companies that also make single lens reflex cameras.

6.   It uses a single lens, special goggles and computer processers to simulate three dimensions.