To See or Not to See...

Vision is the primary sense used in daily life. How do we "see" the world? Do we actually "see" it or rather "perceive" it? Or is it one and the same thing? How do people with optical eye defects perceive the world? Can normally sighted people partake in their experience? If you are blind or become blind, are you blind forever? On Earth and in the spaceflight environment, there are many effects and conditions that may impair your vision or lead to irreversible vision loss or blindness, especially if undetected. The human eye and vision system can be likened to a camera consisting of an optical lens system (cornea and eye lens), film or sensor (retina), and an image-processing unit (retina and visual cortex). The malfunctioning of only one of these components will impair your vision. This paper will touch on the above topics and have (some of) the answers.