The experiment of Hecht, Schlaer and Pirenne Flashcards
what is a photon
to describe light quantum, which is electromagnetic radiation existing in these discrete wave-packets
what is the equation to calculate the energy of a single photon
E=hc/wavelenght
if 20 degrees eccentricity on the temporal retina is the most sensitive area, where will the stimulus be prsented
20 degrees eccentricity at the nasal visual field
what is the source of chromatic aberrations
shorter wavelenghts will bend more through a certain media than long wavelenghts
what is dispersion
refractive index is wavelength-dependent which allows for the wavelengths of a light source to be separated
how does the monochromator use dispersion
the path for each wavelenth changes due to the refractive index, to make the wavelenths fall on diff areas of the retina
what are we observing in a monochromator
spectral sensitivity-in photopic conditions we have diff sensitivies to diff wavelengths and we can observe this using the monochrom at diff wavelengths=> why some wavelengths appear brigher than others
what is a neurtral density filter
made of a materia that reduces the intensity of light. able to equally reduce the intensity of all wavelenths in the spectrum
what are density filters that reduce a certain region in the visible specturm called
colored filters
how are neutral density filters describeD? what is the euqations
optical density
OD= -log10(I/Io)
I=transmitted light intesnsity
Io=incident light intesntiy
a neutral density filter of OD=1 transmits ___% of incident light
OD=2 transmits ____% of incidnet light
10%
1%
what does the mechanical chopper control
by controlling the speed of the chopper, we can control the duration of the light going through the slit; when and for how long the light is transmitted through the system
what is teh aperature used to control
used to control the visual angle/size of the stimulus
-in the experiment, used to control the size of the img on the subjects retina when the pt is sitting at a defined dist away
what does the artificial pupil onctrol
control pupil diameter among subjects and therefore controls retinal illumination
-gives the same pupil size for each subject so they all receive the same ret ill
how much % are photons reflected back due to corneal reflections?
absorption by lens and vitreous?
how much % of photons not absorbed by rhodopsin? (cones, extracell space btwn photorecep, RPE pigment)
3%
50%
80%
