It is known by history that Einstein was fascinated by the nature of light,and from age of 16 he constantly questions himself about what he would see if he was to ride on a beam of light? This question stayed with Einstein through is university years(although went to polytechnic of Zurich)!
Einstein soon realize that his question was a basic flaw and that he could not travel at c.
Now let's assume that one could travel at speed c and still retain his human vision and other features but remaining massless so to agree with E=mc2, what will one see? How will the universe appear?
Disclaimer: the above question is not a theoretical valid question but was set up to see what possibly one could see, in other words,to stare ones imagination.