To give you an idea of the different possibilities, we show you are the different types of lenses we have on offer. We have a large range of monofocal (single vision) lenses in stock. These standard lenses are always made of plastic, are scratch-resistant and non-reflective. If we do not have the lenses of your strength, measured by our experts, in stock, we will order them from the factory and we will cut these lenses in-house to your very vision needs!
These are single-strength lenses, available in plus and minus, for long-sighted and short-sighted people respectively.
A visible reading part has been made in the underside of these glasses. To be able to read properly, you have to look through the underside of the glasses. As soon as the eyes move towards or away from this reading area of the lens, a slight image jump takes place, i.e. a sudden change in the sharpness and depth of vision. Bifocal lenses are therefore useful when you need sharpness for both distant and near vision.
In trifocal glasses, three different kinds of sharpness are cut into the glass, with a beam in the middle for correct sharpness within reach. At the bottom you can read sharply, at the top you can see things sharply in the distance. With trifocal lenses, image jumping occurs when the eye moves across the lens.
Multifocal lenses are also called varifocal lenses. Of this type, Varilux lenses are probably the best known, but at Siefers Opticum, you will find many more brands. This type of lens has an infinite number of strengths, because thanks to a special technique, it is cut smoothly from zero strength to reading strength. When the eyes move over the different parts of the lens, no image jump occurs.
With longline lenses, the reading part is not cut into the bottom of the lenses, but into the core. The sharpening is done in such a way that no image jump occurs when the eye moves from the core to the fringe of the lens. So the image will not suddenly jump, but gradually shift its depth. Longline lenses are ideal for e.g. dentists, lab technicians, electro/ICT technicians and surgeons, people who, during a good length of time, need to do accurate work within easy reach. These are also professions in which image jumps can have very undesirable consequences.