Reason for unique
eyes and large head of Alien Reports
Astronaut Brain Study Shows Space flight May Damage Eyesight.
Brain scans of NASA astronauts who were in space for more than a
month revealed potentially serious abnormalities that could set back
plans for longer deep space missions. Researchers from The
University of Texas Medical School in Houston scanned the eyes and
brains of 27 astronauts who had spent an average of 108 days in
space, either on space shuttle missions or aboard the International
They found that those who spent more than a month in space were more
likely to suffer from intracranial hypertension -- a potentially
serious condition that occurs when pressure builds within the skull.
The symptoms included excess cerebral-spinal fluid around the optic
nerve in 33 percent of the astronauts studied, while a fifth showed
a flattening of the back of the eyeball, which affects the ability
to focus, research published in the journal Radiology showed.
The scans also showed that 15 percent of the astronauts had a
bulging optic nerve and 11 percent experienced changes to the
pituitary gland, which is located between the optic nerves and
secretes and stores hormones that regulate a variety of important
Professor Larry Kramer, lead author, said, "The MRI findings
revealed various combinations of abnormalities following both short
and long-term cumulative exposure to microgravity also seen with
idiopathic intracranial hypertension."
Kramer said the impact of space travel on astronauts' brains and
eyes represented a "potential limitation to long-duration space
Bone mineral loss and temporary muscular aches have been known to
affect astronauts in the past and NASA was now focusing on concerns
over the eye health of its space flight corps.
Dr. William Tarver, chief of the flight medicine clinic at NASA's
Johnson Space Center, said, "NASA has placed this problem high on
its list of human risks, has initiated a comprehensive program to
study its mechanisms and implications, and will continue to closely
monitor the situation and added that no astronauts have been
considered ineligible for space flight duties as a result of the