Color Vision Overview

Color Perception

Integral to daily life, influences decisions and emotional associations.

Evolutionary Advantage

Assists in locating food, crucial for survival.

Visible Light Spectrum

Range of light humans see, 400-700 nanometers.

Selective Reflection

Objects reflect specific wavelengths, influencing perceived color.

Trichromatic Theory

Young and Helmholtz's theory with three cone types for color vision.

Cone Sensitivity

Different cones for short, medium, and long wavelengths.

Color Vision Deficiency

Impaired color perception, categorized as monochromats and dichromats.

Ishihara Plates

Used to test red-green color deficiencies.

Opponent Process Theory

Color vision based on opposing pairs like red-green, blue-yellow.

Monochromats

Experience true color blindness, see in shades of gray.

Dichromats

Have two types of receptors, limited color perception.

Protanopia

Missing long-wavelength cones, struggle with red perception.

Deuteranopia

Lack medium-wavelength cones, affecting green perception.

Tritanopia

Missing short-wavelength cones, impacting blue perception.

Anomalous Trichromats

Have three receptor types with varying sensitivities.

Tetrachromacy

Possess four receptor types, potentially perceiving more colors.

Genetic Links

Color vision deficiencies often have genetic origins.

Color Afterimages

Phenomenon supporting opponent process theory.

Simultaneous Contrast

Contrasting colors affect perception, aligns with opponent process theory.

Combination of Theories

Trichromatic and opponent process theories explain color vision complexities.

Food Foraging Example

Color aids in quickly identifying food items.

Ishihara Plates

Used to assess ability to distinguish numbers in color dot patterns.

Overlap in Sensitivity

Allows perception of a wide range of colors.

Behavioral Evidence

Matching tasks show need for three wavelengths for full color perception.

Physiological Evidence

Three types of cones with different photopigments.