 The eyes of slow lorises are forward @-@ facing , which gives stereo vision . Their eyes are large and possess a reflective layer , called the tapetum lucidum , that improves low @-@ light vision . It is possible that this layer blurs the images they see , as the reflected light may interfere with the incoming light . Slow lorises have monochromatic vision , meaning they see in shades of only one color . They lack the opsin gene that would allow them to detect short wavelength light , which includes the colors blue and green . 
