Laser eye protection in a contact lens using plasmon resonant nanoparticles

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