(word processor parameters LM=8, RM=75, TM=2, BM=2) Taken from KeelyNet BBS (214) 324-3501 Sponsored by Vangard Sciences PO BOX 1031 Mesquite, TX 75150 July 5, 1990 Space Vision Anomalies A Review of the Literature by LAMBERT T. PARKER courtesy of Double Helix BBS at 212-865-7043 Ocular & Visual changes in space. Before we begin talking about the odd effects of space on vision, we need to agree on some definitions. These are: VISUAL THRESHOLD: the minimum amount of light that elicits a sensation of light. VISUAL ACUITY : the degree to which the details and contours of objects are perceived. Visual acuity is usually defined in terms of minimum resolvable separation. Threshold is a complex phenomenon, depending heavily on conditions within the eye and in the surrounding environment. Conditions such as optical factors, the state of the image forming mechanisms of the eye;retinal factors, such as the state of the cones; stimulus factors such as illumination, brightness of the stimulus, contrast between the stimulus and the background, length of time exposed to the stimulus, and so on; and other, random factors. Minimum separation is the shortest distance by which two lines can be separated and still be perceived as two lines. People with sharp vision can resolve lines which are very close together. People with less sharp vision must either move closer to the target (increasing the apparent separation), or move the lines farther apart (increasing the actual separation). Taken together, these two measures are reasonably accurate measures of the overall state of a persons vision. It is said eyes are the windows into man's soul. The importance of the organs of sight cannot be over-emphasized. The visual system, eyes and brain, are a navigation system which can measure distance through stereoscopic vision, detect motion, focus from the tip of the nose to infinity, recognize a multitude of colors, shades and shadows, adapt to a wide range of lighting conditions, coordinate an average 70 kg male/female in motion as complex as a ballet or as exacting as threading a needle. It operates through a zillion neural interfaces in a system thousands of times more powerful than the most advanced computer, and does it all without any conscious thought at all. You simply decide that you want to do thus and so, and it is done. Page 1 For all its amazing versatility, vision is a specialized system. Human visual hardware is a result of a billion years of evolution within the earths atmosphere where light is scattered by molecules of air, moisture, and particulate matter. But as we ascend into our atmosphere light distribution is changed, due to the decreasing density of the air. The visual system receives information differently. Sometimes this can result in odd, even astounding, visual effects. Gemini 4 astronaut Edward White reported seeing networks of roads during his space walk, and so did cosmonaut Nikolayev from Vostok 3 as early as 1963. "During the day, the earth has a predominantly bluish cast.....I could detect individual houses and streets in the low humidity and cloudless areas such as the Himalaya mountain area. I saw a steam locomotive by seeing the smoke first..... I also saw the wake of a boat on a large river in the Burma-India area...and a bright orange light from the British oil refinery to the south of the city (Perth,Australia.)" The above observation was made by Gordon Cooper in Faith 7 [1963] and it generated much skepticism in the light of the thesis by Muckler and Narvan "Visual Surveillance and Reconnaissance from Space Vehicles" in which they determined that a visual angle of ten minutes was the operational minimum possible for humans, and that the minimum resolvable object length [M.R.O.L] at an altitude of 113 miles would be 1730 ft. This limitation of acuity was revised the next year to 0.5 seconds of arc for an extended contrasting line and 15 seconds of arc for minimum separation of two points sharply contrasting with the background. So how could these astronauts "see" objects much smaller than this? The answer is that the eye isn't the entire visual system. There is a mind intimately connected with the eye, and the mind is capable of inferring details where none can be seen. Orbiting at 237 miles in Skylab it was possible to see the entire east coast [Canada to the Florida Keys] and resolve details of a 500 feet long bridge based on inference. Of interest is the fact that even though a mechanical eye [camera system] can resolve objects greater than fifty times better than the human eye, without human ability to infer, people, possessing the ability to infer, can match that performance--or even surpass it. That leads us to our first conclusion, the first observed difference between visual performance on earth and visual performance in space: Visual acuity in space exceeds that of earth norm when objects with linear extension such as roads, airfields, vessel wakes, etc. An ability called by some the "Search Light Effect". This is a positive factor. In space, vision is sharper than it is on the ground. The next factor is not so positive. In fact, it can be a grave danger to anyone working in the space environment. We judge distance by the mechanism of stereoscopic vision. It works by fusing the twin images impinging on the eyes, combining them into one image, and producing a sense of distance. This system relies on reference points. One object overlaps another, or the images Page 2 received in either eye are slightly different. You can demonstrate this to yourself by simply looking into a mirror. As you look, close one eye. You see one side of your face slightly more than the other. Now look through the other eye. You see the other side of your face. Now, with both eyes open, you can see your face and somewhat of both sides, and along with that visual impression you have a sense of how far away you are from the image. The sides of your face, perceived unequally in either eye, are reference points for distance. In space one has to deal with a poverty of reference points. For hardware evolved in a reference oriented paradigm this poses a grave problem, once out of the space craft gazing outward the eye can only fix on the stars [without even a twinkle] which for all practical purpose is at infinity. This induces a state called "Empty field myopia". Empty Field Myopia is a condition in which the eyes, having nothing in the visual field upon which to focus, automatically focus at about 9 feet. An astronaut/cosmonaut experiencing empty field myopia focusing at 9 feet would be unable see objects at a range as close as 100 feet. If another spacecraft, satellite, meteorite or whatever entered his field of vision, he or she would not be able to determine either its size or its distance. That is our second conclusion: Vision in space is very subject to a lack of visual reference points, a condition which induces a state of visual "neutral lock" known as empty field myopia. Is there a solution? Man does not face any hostile environment in his birthday suit, the clothing industry and walk-in-closets say it all. In space we will wear our exoskleton just as we wear winter jackets in winter. We will wear our helmets with visors to maintain our internal environment, filter out all those nasty rads etc. Since empty field myopia is a result of loss of reference points, why not just build them into the visor itself? Give the eye points of reference. Create a virtual reality? This line of speculation leads to amazing concepts. To learn more about the concept of virtual universe in the helmet read: Journal: Air & Space, [Smithsonian Publication] Article: Big Picture by Steven L.Thompson. illustrated by Dale Glasgow. About the creation of a virtual universe with new computers and software in the helmets of F-16 fighter pilots--this is not a theoretical posibility but a reality. There is another downside to the performance of human visual systems in space. One aspect of a adaptation to microgravity [space sickness] is an increased dependence on visual as opposed to vestibular mechanisms in the stabilization of the retinal image during head movement. This phemonemon only underscores the importance of being aware of our visual ability. This is our third conclusion: Microgravitational effects on the human visual/orientation system can cause unpleasant or even debilitating effects. Page 3 As if that weren't enough, studies done by the Russians on cosmonauts on effects of perception of colors in space suggests a reduction in the perception of brightness of all colors. Greatest degradation seems to occur in purple, azure, and green. Conclusion number four: Visual perception of color is impaired in the space environment, with implications for color coded reference systems. And, finally, there are the light flashes. Not the so-called fireflies noted in orbital flights by astronauts [shown graphically in the movie "The Right Stuff"] but lights perceived as faint spots or flashes seen after dark adaptation in the cabins of the Apollo missions. These light flashes described as white or colorless have been classified as three types: 1) Described as "spots" or "starlike" objects 66 % of the time. Appearing in both eyes simultaneously or one eye at a time. 2) Described as "streaks" 25 % of the time. 3) Described as "lightning discharge seen behind clouds" 9 % of the time. It is of interest that the very same astronaut who reported them in the Apollo flights failed to see them in previous Gemini flights. After the Apollo flights this phenomena was noted by the crew of all three Skylab missions especially when they crossed the South Atlantic Anomaly. W.Zachary Osborne, Ph.D., and Lawrence Pinsky, Ph.D., at the University of Houston & J.Ver on Bailey at Lyndon B. Johnson Space Center conducted an investigation of this phenomena and concluded that it was due to heavy cosmic radiation penetrating the craft. The fact that the effect was noted only after the eyes were dark adapted confirmed retinal interaction rather than interaction with optic nerve. Which brings us to our last conslusion: Radiational effects and light flashes, can be a problem to future space travelers. These are not the only effects that we will (literally) see as we explore and move out into space. They are, however, a significant divergence from normal human vision, and must be taken into account in both the planning and execution of future construction workers living and working in space, and it must be taken into account. Failure to do so can be costly, both in terms of time lost and valuable equipment damaged or destroyed. It can also be fatal. To the construction worker who fails to see a moving object coming toward him. To the pilot that misjudges an approach, or to anyone in that environment relying on vision for safety. Page 4 These are the effects: Unusual visual acuity Empty field myopia Space sickness Lost color perception Light flashes They must be taken into account during the planning and execution of any space mission. Failure to do so can be costly...or fatal. -------------------------------------------------------------------- If you have comments or other information relating to such topics as this paper covers, please upload to KeelyNet or send to the Vangard Sciences address as listed on the first page. Thank you for your consideration, interest and support. Jerry W. Decker.........Ron Barker...........Chuck Henderson Vangard Sciences/KeelyNet -------------------------------------------------------------------- If we can be of service, you may contact Jerry at (214) 324-8741 or Ron at (214) 484-3189 -------------------------------------------------------------------- FINIS Page 5