Our eye cells detect the wavelength of light rather than its frequency. The human eye is sensitive to a narrow range of wavelengths within the electromagnetic spectrum, known as the visible spectrum. The visible spectrum ranges from approximately 400 nanometers (violet/blue) to 700 nanometers (red).
Different wavelengths within the visible spectrum are associated with different colors. When light enters our eyes, specialized cells called photoreceptors, specifically the cones, are responsible for detecting and responding to different wavelengths of light. There are three types of cones in our eyes, each most sensitive to different ranges of wavelengths corresponding to the colors red, green, and blue.
When light of a particular wavelength enters the eye and interacts with the cones, it triggers a neural response that our brain interprets as a specific color. The brain combines the signals from these different cones to perceive a wide range of colors.
So, while the frequency of light is related to its wavelength, our eye cells directly detect and respond to the specific wavelengths of light to perceive different colors.