It is not true that invisible men have to blind. It it true that light passes through the retina of an invisible man, but in most "invisible man" movies I've seen one way of locating an invisible man is using night-vision goggles witch show the sub-red part of electromagnetic spectrum. This fact suggests that whatever turned him invisible, it rendered him hollow only to so called visible part of electromagnetic spectrum with wavelenght between 380 and 780 nm. Shifting the range of wavelenght sight to sub-red (780nm to 1mm) during the process of making invisible could produce a proper seeing (or even better) invisible man.<br /><br />And last but not least the invisibility in James Bond "Die Another Day" works only from a long distance and uniform background. Otherwise changing the point of view will uncover hidden object.