Question

At which wavelength of light are the blue and green cones equally stimulated? What color is this light?

Short answer

The wavelength of light at which the blue and green cones are equally stimulated is approximately \(485 \, nm\), and the color of this light is cyan or aqua.

Step-by-step solution

Understanding the Human Eye's Cone Cells

The human eye has three types of cone cells responsible for color vision, which can be roughly classified as red cones, green cones, and blue cones. Each type is sensitive to different regions along the visible light spectrum. The sensitivity of these cones varies based on the wavelength of the incoming light.

Finding the Wavelength for Equal Stimulation

To find the wavelength at which the blue and green cones are equally stimulated, we need to determine the wavelength at which the sensitivity of the blue cones and the sensitivity of the green cones intersect. We can observe this from the response curves of the cone cells in the eye. According to the CIE Standard Observer functions, we generally have three types of cone cells with the following peak sensitivities: - Blue cones (S-cones): Around 420 nm - Green cones (M-cones): Around 530 nm - Red cones (L-cones): Around 560 nm Note: These values are approximate and can vary from person to person. We first need to find the point at which the response curves of the blue and green cones intersect. After looking at the response curves of these cone cells, the intersection lies at approximately 485 nm.

Identifying the Color of the Light

With the wavelength determined to be approximately 485 nm, we can now identify the color of the light. In the visible light spectrum, a wavelength of 485 nm corresponds to a color between blue and green, often referred to as "cyan" or "aqua."

Conclusion

The wavelength of light at which the blue and green cones are equally stimulated is approximately 485 nm, and the color of this light is cyan or aqua.