Contact lenses offer many advantages, both optically as well as of a cosmetic nature. The more pronounced the defective vision is, the greater can be the optical advantages of contact lenses. This applies particularly in the case of short-sightedness (myopia), but also in the case of far-sightedness (hyperopia) and astigmatism caused by corneal irregularity. Between the surface of the cornea and the surface of the back of the contact lens, a so-called “tear lens” is formed, which as part of the optical system, particularly supplements the effect of the hard (stable) contact lens.
Even significant defective vision can, therefore, in contrast to spectacles, be corrected with significantly thinner contact lenses and without greater problems. Also the illustration errors are stronger spectacles, e.g. rim distortions, and normally do not occur in the case of contact lenses. A further disadvantage of spectacles is the magnifying or reducing effect. This effect is based on the plus glasses magnifying the image on the retina and minus glasses reducing the image on the retina.
Since contact lenses accompany each eye movement and their centre always lies in front of the pupil, there are no blurred edges, and the field of vision remains unrestricted. Through this quality, it is possible, exactly as in the case of spectacles (gliding sight spectacles, bifocal spectacles), to use multifocal contact lenses.
These contact lenses thus render possible a focussed vision both at a distance as well as at close quarters. For sportsmen and women, the freedom of movement is decisive. Contact lenses have a great advantage here. The risk of injury by wearing spectacles ceases to exist. Moreover, contact lenses cannot get dirty like spectacles; even in rain and snow, the wearer always has clear vision. Anyone who works with equipment, e.g. a camera or a microscope, likewise copes better when wearing contact lenses, in contrast to spectacles, contact lenses are not “in the way”. Compliance with safety provisions, such as the wearing of protective goggle or safety helmets is also easier.