Soft lenses were also put into a mould and various masks were applied, often with striations to mimic the iris pattern and then different coloured dyes were introduced to produce a coloured lens that mimicked a customer's original eye. Hand painted lenses were tried to mask injuries for example. To achieve colour fastness, reactive dyes can be attached covalently to the spine of the polymer chain, either with the dye first infused into the lens and then fixed, or by attaching it to the surface of the lens.Īttempts were made in the 70's to use coloured soft contact lenses for clinical reasons. Materials can be swelled to allow entry for larger dye molecules, and then contracted again to trap the colour in the material. Without such fixation, dyes infused into hydrogel lenses can diffuse back out during wear or cleaning, with a loss of colour. In 1969, Professor Otto Wichterle patented the idea of diffusing a coloured dye into a hydrogel (soft material) from one surface, and a precipitant from the other surface, so that when they met, an insoluble colour was precipitated in the middle of the lens matrix, or deposited between two polymer layers. The Early Days of Coloured Lenses - Hard lensesĭevelopment of hard contact lenses and rigid gas permeable (RGP) contact lenses in the 1970's and 1980's, soon moved onto introducing a handling tint with about 5% absorption to make the lenses more visible during handling, without the intent of changing eye colour. The evolution of colour contact lenses has been varied and interesting. This fashion aspect of contact lenses could be regarded as an extension of the use of fashionable and colourful frames for optical correction by spectacles. Colour contact lenses enable people to extend this flexibility of appearance to their eyes, making it possible to use coloured contact lenses to change the colour of their eyes and complement an outfit, or create a natural enhancement to the eye's appearance. The ability to change clothing according to mood and occasion has led to the existence of a substantial fashion industry with a large following.
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