Sensitivity of the Human Eye to Light

C is the concentration of limiting reactant in mol/L, c is the chemiluminescence quantum yield in ein/mol, and P is a photopic factor that is determined by the sensitivity of the human eye to the spectral distribution of the light. Because the human eye is most responsive to yellow light, where the photopic factor for a yellow fluorescer such as fluorescein can be as high as 0.85, blue or red formulations have inherently lower light capacities. 

The tristimulus values result from the natural sensitivity of the human eye to colors. There are three types of sensor cells in the human eye that respond to three regions of the visible light. The basic idea... 

The filament in a light bulb is made of tungsten because its melting point is so high. Operation of the bulb near its maximum temperature enables the value of A.(maX) to shift to shorter wavelengths, i.e. closer to the sensitivity of the human eye. 

Three common classes of instruments are used for measuring the amount of incident light (1) photometers or light meters, which measure the available illuminating power, a quantity related to the wavelength sensitivity of the human eye (2) quantum or photon meters, which measure the number of photons and (3) radiometers, which measure the total energy of the radiation (Fig. 4-4). 

The color of the ion is complementary to the light absorbed. Although the prediction of the color from the data is not absolute, since the color depends not only on the wavelength of the absorption maximum but also on the shape of the whole absorption band and on the color sensitivity of the human eye, fairly reliable conclusions can be drawn. The absorption, which peaks in the blue-violet region of the spectrum, would be expected to cover most of the blue region and part of the green. The color would be expected to be yellow. 

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