With special filter lenses for medical applications, also known as cut-off filters, ZEISS rounds off its range of filter lenses.
Studies have shown that, in certain diseases of the retina, special filter lenses often enhance contrast and reduce the time required to adapt to different light conditions.
Special filter lenses for medical applications completely absorb part of the visible spectrum. Receptors in the eye which are sensitive to this region are deliberately "underexposed". The contrast between those receptors subjected to maximum, and those subjected to minimum exposure is increased. Studies have shown that, in certain diseases of the retina, special filter lenses often enhance contrast and reduce the time required to adapt to different light conditions.
There are no uniform, objective criteria for the prescription of special filter lenses. Instead, the most suitable lens is usually found by trying out the various options available, especially for such degenerative eye disorders as retinitis pigmentosa or diabetic retinopathy. Patients subjectively compare and assess the visual comfort provided by the different types of filter lens available. Patients decide what filter lens is most suitable for their needs by comparing and assessing the visual comfort provided by various filter lenses. Binocular lorgnettes for mounting in front of the eyes or a filter clip for attaching to spectacles are available for this purpose.
Many patients require special filter lenses for different light conditions. This is why they often have several pairs of glasses or filter clips with different special lenses.
The transmission of the special filter lenses F 60, F 80 and F 90 and F 540,
F 560 and F 580 for medical applications has been optimised so that part of the visible shortwave spectrum is absorbed.