Transmittance characteristics of tinted hydrogel contact lenses intended to change iris colour

Tinted ophthalmic media can have significant effects on the ability of persons with normal or defective colour vision to detect and recognise coloured objects, and this can have safety connotations in driving and other areas. The luminous transmittance of ophthalmic media can have a significant effect on die ability to detect low contrast objects. While tinted spectacle lenses and sunglasses can be removed when not required, contact lenses are less likely to be removed when their use is inappropriate. Contact lenses designed to change iris colour represent the darkest tints to be found in prescription contact lenses and, in order to prescribe appropriately and advise on suitability, a practitioner must be aware of the transmittance characteristics of the tints prescribed or supplied. In this paper, the transmittance characteristics of iris‐tint lenses currently available are reported to aid the practitioner in their use. The authors also make reference to the possible visual consequences of unfortunate combinations of contact lens tint, sunglasses and tinted windscreens and warn practitioners.