Weight optimization here stands for optic design, i.e. creation of a new optical system, on the assumption that weight should be a minimum! This will be done only by means of traditional design methods, that is excluding the use of aspherical surfaces, plastic materials, mirrors, diffractive or similar elements! This demand for lowest possible weight is important with systems, that must be transported for example into space, as well as with handheld systems, for instance binoculars, riflescopes, but also with photographic lenses. Up to now, no theory exists which describes how this problem can be solved. Here, the essay begins with the fundamentals, after that the basic facts related to the weight of a lens are discussed, as well as references made to publications. At the end, two design examples are given, the first being a binocular. The second example shows, that even in hopeless cases sometimes a solution can be found.
The Glasgow Lens Design Problem is ofcurrent interest in a special field of optics: Microlithography. This field is accompanied by high economic interests. Companies often do not allow their employees to publish their work. And the problem perhaps was too special: a lens consisting only ofinirrors was asked. This reasons (and probably additional ones) led to the situation, that only 6 solutions were received. Nevertheless, this few solutions show the range ofpossibilities given by this statement of the problem.