[6] Foster and his group are credited with key contributions to the discovery of the non-rod, non-cone, photosensitive retinal ganglion cells (pRGCs) in the mammalian retina which provide input to the circadian rhythm system.

Foster attended Heron Wood School in his native Aldershot and studied at the University of Bristol and graduated with a Bachelor of Science (BSc) in Zoology in 1980.

[7][8] From 1988 to 1995 Foster was a member of the National Science Foundation Center for Biological Rhythms at the University of Virginia, where he worked closely with Michael Menaker.

[4] In 1995, he returned to UK and started his own lab at Imperial College, where he became Chair of Molecular Neuroscience within the Faculty of Medicine.

Foster concluded that rods and cones are unnecessary for entrainment to light, and that the murine eye contains additional photoreceptive cell types.

Later studies showed that melanopsin expressing photoreceptive retinal ganglion cells (pGRCs) were accountable for non-rod, non-cone entrainment to light.

[3] Foster was appointed Commander of the Order of the British Empire (CBE) in the 2015 New Year Honours for services to science.