But here's a stab. The only light we see is that which enters the eye and strikes the cornea. We mostly see light that is reflected off objects unless we are looking directly at the light source. You also asked how light can travel where there is no medium. This gets a little complicated by here goes.
Light consists of electromagnetic waves of a certain band of frequencies.
That is quite a mouthful so we will take it in pieces. An electric charge will exert a force on another electric charge. For example, pieces of styrofoam stick to you and you can't get rid of them. The cling because of the attraction of electric charges. This force, described mathematically, is an electric field.