The human eye can detect wavelengths between 400 nm and 700 nm. The sky appears blue (490 nm) due to the scattering of visible light by particles in the atmosphere. Given this information, it is reasonable to conclude that:

In the electromagnetic spectrum, the visible spectrum is the part, which is perceptible to the human eye. The electromagnetic spectrum in this array of wavelengths is known as simply light or the visible light. A general human eye will react towards the wavelengths in the range between 380 to 740 nm. A human eye sees the sky as blue that comes in the wavelength 490 nm because of the scattering of the visible light by the particles in the atmosphere. This concludes that 490 nm is the sole wavelength, which is reaching the eye.