 With the increase of computer use, VDU glasses were developed. They provide a clear vision of the intermediate zone at a distance of approximately 70 centimeters, which is closer than distant vision at a distance of more than 2 meters e.g. driving, but further than near vision at a distance of 40 centimeters e.g. reading, so the computer screen is seen clear without the need for excessive focusing effort or bad postures. Progressive lenses have some lens power for this intermediate zone as well, but this zone might not be large enough for comfortable and ergonomic computer work. VDU glasses are often progressive glasses as well, so they can be used to read and see things beyond the computer screen clear during computer work. 