Transmission tints - modify the natural colour of the iris.
Reflective tints - are able to change the colour of the eye more dramatically, e.g. Brown eyes blue.
Cosmetic iris prints - can be used for startling changes to the natural iris appearance.
Astigmatism can be due to an irregularity of the outer or inner optical surface of the eye. It causes distorted vision. Small amounts of outer (corneal) astigmatism may be corrected with standard hard/gas permeable lenses. The more advanced designs of contact lenses that are now available allow even high degrees of both forms of astigmatism to be corrected.
People who require separate pairs of spectacles for distance and reading, or who wear bifocals, can be corrected with contact lenses in the following ways:
Contact lenses for distance vision with low power reading spectacles for close work. Bifocal/Multifocal contact lenses - these lenses are designed to produce an alternating or simultaneous focus of distant and close objects.
Monovision - This facilitates the natural bias in many eyes to focus either for distance or reading. It can enable many people to do
without spectacles altogether without the complexity of bifocal lens designs.