Background

Many artificial sources of light tend to be mixes of multiple wavelengths and can also be classified as white light. Normal incandescent light-bulbs tend to emit more long-wavelength light than short-wavelength light. This gives incandescent light-bulbs their characteristic yellow color. Fluorescent light-bulbs tend to have the opposite pattern, giving them their slightly blue hue. See the picture below where two different white lights are next to each other, one with more long wavelengths, in lounge area, and one with more shore wavelengths, in the hallway. Being next to each other you can see the differences in these whites more easily.

In this illustration, you can simulate changing different light sources that are white.

Instructions

Full Screen Mode

To see the illustration in full screen, which is recommended, press the Full Screen button, which appears at the top of the page.

Illustration Tab

On the Illustration tab, you can adjust the parameters and start a simulation of dark adaptation.

Settings

Below is a list of the ways that you can alter the illustration. The settings include the following:

Illumination Type: preset standard types of illumination. Press the desired button: Incandescent, Fluorescent, Noon, or Twilight, to see the image illuminated with that type of light.
Illumination Control: use these sliders to create any illumination source that is possible on your monitor. The colored square at the end of the red primary slider shows the color of the current illumination.
How Display: Single refers to showing only one image which has all your current settings. Compare will put the original photopic color on the left and the image in the current eye state on the right.
Use Your Own Image: allows you to upload your own image to simulate the Purkinje Shift.

Reset

Pressing this button restores the settings to their default values.

Proceed to Quiz