Nanoparticles that facilitate imaging of biological tissue and methods for formulating the nanoparticles are provided. A film made of tantalum silicides is suitable to use as the second layer of the halftone phase shift film. Light rays emanating from structures within the eye pass through the cornea and contacting portion of the lens and first reflect from the anterior reflecting surface as a positive reflection in a posterior direction. Most applications that utilize nanoparticles can benefit from this invention.