As the use of lasers proliferate in military and civilian applications, the importance of laser eye protection becomes increasingly significant. Of particular relevance is protection from non-visible laser sources operating in the near-infrared, as it is impossible to determine when the eye is being exposed to such harmful radiation. Current technologies for laser eye protection, such as dyes or reflective coatings of visors/glasses, are generally bulky, which presents a challenge for use and integration with oxygen masks, helmets and night vision apparatus. A contact-lens based laser eye protection system would offer the advantage of minimal modification of current equipment to provide protection against laser exposure.
A laser eye protection system has been developed based on the unique optical properties of gold nanoshells. Gold nanoshells consist of a dielectric silica core, surrounded by a thin (nm) shell of gold. By adjusting the core size and the shell thickness, these nanoparticles can provide high extinction levels throughout the near-infrared region of the spectrum. Unlike some organic dyes, the particles are photostable and non-toxic, increasing the practical life of the lens. The design and fabrication of a soft contact lens containing nanoshells is described. The optical and physiochemical properties are compared to a standard soft contact control. The results of preliminary toxicity studies are also presented