With respect to electromagnetic waves, the human eye is sensitive to

In an electromagnetic wave, the energy carried by the electric field component and the magnetic field component is equal, but the force exerted on charged particles (such as electrons in the photoreceptor molecules of the retina) by the electric field is much larger than that by the magnetic field at typical wave speeds (the ratio is c, the speed of light). Therefore the photochemical processes in the eye that produce vision are triggered almost entirely by the electric field component of light waves. Hence the human eye is sensitive to the electric field only.