Standard: Explain how the human eye sees objects and colors in terms of wavelengths What am I learning today? How are wavelengths detected by the human eye?

How will I know that I learned it? I will know which part of the eye affects how we see color and why this is a good test for colorblindness.

Awesome science… This is not actually moving!!

Light, Color and Your Eyes oDtbSk

Type of matter in an object determines the amount of light it absorbs and reflects.

1.Opaque materials – absorbs or reflects all light, you can not see through them 2.Transparent materials – allow light to pass through, you can see through them 3.Translucent materials – allow some of the light to pass through; you can not clearly see objects through them

Red Orange Yellow Green Blue Indigo Violet Light waves in the visible spectrum arranged from longest wavelength to shortest wavelength.

The color appearance of any object is due to the wavelengths of light that are reflected from the object and picked up by our eyes.

1.Black objects absorb all the colors of the visible spectrum.

2. Blue jeans appear to be blue because all the colors except blue are absorbed and blue is reflected to your eyes

3. White objects appear white because they reflect all the colors of the visible spectrum.

Even though the visible spectrum consists of seven different colors, all of the color seen by the human eye is a mixture of the three primary colors: red, green, and blue.

Red, green, and blue are the primary additive colors. When mixed together in different proportions, you can make just about any color. When mixed in equal proportions (added together), the three primary colors yield white light.

A pigment is a colored material that absorbs some colors and reflects others. The primary pigments are: 1. magenta 2. yellow 3. cyan

Cyan, Magenta, and Yellow are the primary subtractive colors. These colors are combined to produce print media and photographic film. When the subtractive primary colors magenta, cyan, and yellow are added together, they form the color black. ubtractive.html

When light enters your eye, it is focused on a special “screen” at the back of the eyeball. This screen is called the retina.

It is made up of two different types of nerves cells, rods and cones. The rods are sensitive to dim light and are useful for night vision. Cones are useful during the daylight and they help to distinguish color because they absorb a different range of wavelengths.

There are three types of cones: 1. Red cones – absorb mostly red and yellow 2. Green cones – absorb mostly yellow and green 3. Blue cones – absorb mostly blue and violet

Examples: When you look at white T-shirt, all three cones are stimulated When you look at blue jeans, only the blue cone is stimulated When you look at a yellow shirt, both red cones and green cones are stimulated

Color blindness occurs because one or more sets of cones do not function correctly. Try these tests.