Nearly all his independent research relates to understanding light perception and signal transduction by the phytochrome superfamily of light absorbing molecules in plants and, more recently, in microbes. (aspb.org)
Light perception takes place in the cone and rod photoreceptor cells of the retina, a structure at the back of the eye, through a set of proteins denominated phototransduction cascade proteins. (scilifelab.se)
Blindness in both eyes having only light perception, plus loss or loss of use of one lower extremity (wccloans.com)