Nowadays, eyeglasses are not only a vision aid, they also are fashion and design articles for the customers. The customer preference for various forms of spectacle frames grows and is served by the different frame manufacturers. This development leads to an increased effort for the production of adapted eyeglass lenses because of the huge range of the different designs and their manufacturing inaccuracies [1]. Therefore it is absolutely necessary to know exactly the coordinates of the ground of the spectacle groove for grinding the glasses well. One non-contact possibility is the triangulation principle. Therefore often a laser line generator is used. But also a structured LED linear light is possible. For this the linear light has to have a defined width, brightness and sharpness. The linear light on the object, here the groove of the frame, is changed by its surface and is detected by a digital image processing [2]. If more information should be detected within one image a multi linear light could be used. Due to this also a structured LED based light source is an economically priced alternative to a multi laser line generator. Consequently, the focus of this research lies on the necessary width, brightness, sharpness, length and depth of focus of the linear light generated by a LED light source for high-precision measuring. This research has been carried out by extensive computeraided simulations.