Solar Eclipses are usually only partial , i.e., the Sun is not totally covered by the Moon and the light still reaches our eyes. However, since the neighboring surfaces- the sky and the part of the Sun covered by the Moon- are dark and thus sandblast very little or no light, the available light beams of the not-covered part of the Sun are not restrained, as it is otherwise the case when the sky is bright. This means that our eyes are exposed to a still more intensive radiation than normally. One can go blind as a result?

What occurs during this overstimulation?

There are very sensitive substances in the eye which are easily damaged by visible light with too much energy .
Light with larger wavelength (close to the infrared area) is normally absorbed by the pigment layer. However, if this radiation becomes too intensive, then warmth is released, which leads to overheating and these substances are destroyed. We see because of the substance rhodopsin, which consists of the protein opsin and of retinal. Proteins react extremely sensitively to extensive warmth and intensive radiation. They change their spatial structure, which means that opsin is not any more available for the synthesis of rhodopsins. Suddenly the whole nucleus is disintegrated by the large beam of light.
All in all, this means that excitation is no longer possible, and even if excitation were there, it could not be passed to the brain, as the network concerned is blind. In order to escape the danger of a permanent damage of the eye, at least very good sun glasses should be put.
. However special eye protector is much better, which is to be acquired at a small cost. Then this rare event will be beautiful unforgettable.