|Vertical axis is logrithmic. Absorbance coefficients of three types of chemicals found in the human body.
"Accuvein" is the brand name of a tool that uses NIR to help phlebotomists visualize blood vessel. The basic technology of the tool is to scan the skin surface with a near-infrared laser and record images of the resulting reflectance. The tool then replicates the pixel-image by projecting it back on to the surface using a visible laser.
The original NIR laser frequency is chosen based on high hemoglobin absorbance compared to water, skin and fat cells.
Given the mature state of fingerprint recognition, a relatively high degree of discrimination based on recognition of a vein print of your forehead or nose would not be technically challenging.