Given that only about 
% of the energy of incandescent
bulbs is converted into visible light and assuming that each photon
has a typical wavelength 
, I the total
number of photons
emitted by a P=100 Watt bulb during each response time 
of the
human eye. your answer in terms only of the variables
given, Planck's constant h and the speed of light c, (i.e., use
only 
).