Photochromic Contact Lenses

Scientists in Singapore have made a breakthrough in contact lenses. While previous contact lens designs provided no help against the harmful rays of the sun, the new design which has been proposed by this design team is designed to work in a manner that is similar to the Transitions® lenses which were put out in the market in the 1980s. These contact lenses are designed in such a way that they look and feel like the normal contact lenses which many of us wear on a daily basis. The difference between the normal contact lenses and the new lens is that the new lenses are “photochromic”, meaning that they are able to darken under the influence of sunlight.

In designing this lens model, the research team had to consider factors such as the biocompatibility of whatever materials were used in the lens design, the increased possibility of bacterial infection that could result from a poorly designed lens, and the oxygen permeability of the material, which is a very important factor in the comfort level of these lenses. In order to add the transition lens effect to the contact lenses, there was an additional condition of using a dye which is sensitive to changes in brightness. While the lens should be lightweight and flexible, it must be able to withstand the shear forces applied to it every day and the wear and tear it will encounter due to countless times of removing and putting the lens in the eye.

This article is interesting to me, since I wear contact lenses, which have their share of problems when it comes to exposure to bright sunlight. Additionally, from a biomedical engineering standpoint, it is interesting to note that this problem requires the integration of biomechanics, biomaterials, and biomedical optics in order to effectively solve the problem.

Link: http://news.xinhuanet.com/english/2009-11/03/content_12377748.htm

Blesson John

VTPP 434-502