The foveal sensitivity to several near-infrared laser wavelengths was measured. It was found that the eye could respond to radiation at wavelengths at least as far as 1064 nm. A continuous 1064 nm laser source appeared red, but a 1060 nm pulsed laser source appeared green, which suggests the presence of second harmonic generation in the retina.
© 1976 Optical Society of America
David H. Sliney, Robert T. Wangemann, James K. Franks, and Myron L. Wolbarsht, "Visual sensitivity of the eye to infrared laser radiation," J. Opt. Soc. Am. 66, 339-341 (1976)