Maintaining Basic Equipment
Amateur astronomers eyes
are their basic optical instruments. Articles abound on telescope
optics maintenance, but fingers on one hand are enough to count
articles on eye maintenance. More importantly, few, if any, articles
are written on preventing the most common eye problems.
Visual Problems to
By age 65, over 22 percent will have definite evidence of cataracts,
common eye-lens clouding. A similar percentage, albeit not always
the same people, evidence low vision, and a smaller
group will show beginnings of macular degeneration.
A brief description will clarify common preventable problems.
Cataracts: The eye lens slowly becomes cloudy and eventually
opaque. Cataracts involve oxidation of the clear, transparent
lens proteins. They are correlated with excess exposure to ultraviolet
light, so always wear dark glasses in the sun. Cataracts are accelerated
by smoke, smoking, volatile solvents, and mostly by poor dietary
habits, specifically inadequate amounts and varieties of vegetables
Low vision: Low vision simply means that things look dimmer
than they really are. The contrast of extended objects also suffers
markedly, especially in dim light. Low vision means you lose a
magnitude or so when looking at the stars or cant see subtle
details on planets. Low vision occurs in the eye retina, a very
highly specialized nerve tissue that is an extension of brain
tissue. Yes, it is your brains window on the world.
Macular degeneration: A small area on the retina, the macula,
is responsible for focusing the eye. As it deteriorates, the ability
to focus is lost and eventually everything becomes a blur.
Tells the Story
Over four decades ago, scientists noticed that cataract development
correlated with geographic location, lifestyle, and food habits.
Cataracts occur most where the sun is brightest and the upper
atmosphere ozone the lowest. In short, ultraviolet light hitting
the eye lens is the root cause. People whose diets are poorest
in vegetables and fruits, especially those rich in vitamins C
and E and bioflavonoids, have the highest rates of cataracts everywhere.
Confirming studies abound.
Confirmation also comes from the antioxidant composition of the
eye. The eye lens contains about 50 times the vitamin-C and about
35 times the vitamin-E concentrations found in normal blood. We
may ask, Why would nature expend the energy necessary to
maintain those very high levels if they didnt have a survival
Similarly, all tissues are rich in two specific bioflavonoids,
lutein and zeaxanthine. Most experts recommend about 14 milligrams
of each daily. The best sources of lutein and zeaxanthine are
kale, greens, spinach and broccoli. Your mother was right when
she told you to eat your vegetables. You can deduce that the major
protector substances in the eye are obtained from fruits and vegetables.
In short, maintaining good vision requires good relations with
the vegetable kingdom.
It is one more reason why nutritionists say you need at least
three servings of vegetables daily, including one leafy (e.g.,
spinach) and one cruciferous (e.g., broccoli). I strongly
recommend 5 veggies and 4 fruit servings daily.
When you cook vegetables you get about three times as much from
them in nutritional value; especially with the antioxidants. I
know that goes against what most people believe, but people used
to believe the world was flat. Its always better to eat
cooked vegetables than raw. Just dont cook them to soft,
but to a point where they are still crisp.While not a single study
has supported the notion that a pill providing lutein and zeaxanthine
prevents cataracts, a number of excellent studies have proven
that taking vitamins C and E daily, in a multiple vitamin-mineral
supplement or separately, has a definite preventive effect. So,
eat your oranges and drink orange juice, but take a basic supplement
Our parents (genetics) have a major role in everything and macular
degeneration is no exception. However, genetics aside, dietary
factors do have a role here. Think of the retina (including the
macula) as brain tissue, and indirect evidence starts falling
into place. One major chemical component of brain tissue is an
omega-3 oil, docosahexaenoic acid, DHA, for short. The protection
of DHA is also another role for vitamin E.
Indeed, DHA, when seriously short through oxidative destruction,
and especially through poor dietary habits, increases the risk
of macular degeneration and low vision. Similarly, a serious and
prolonged vitamin-E deficiency has a similar effect. So, it is
good news that we have a handle on several significant, interrelated
causative factors. However, subsequent research on low vision
has proven that restoring these substances, so vision is restored,
requires about two years to achieve normalcythat is only
when the problem hasnt reached the point where the condition
is irreversible. Whenever there is a problem involving nerve tissue,
especially brain tissue, damage can occur quickly, but improvement
always moves in slow motion. Both macular degeneration and low
vision prove that point quite clearly. Prevention, as always,
is the best and most effective medicine. One last point about
macular degeneration is that somehow zinc deficiency is involved,
providing another reason to take a daily multiple vitamin-mineral
DHA is one of three omega-3 oils that are essential for health.
We obtain these oils from cold-water (blue skinned) fin fish,
such as tuna and salmon, and very few modern vegetables. Indeed,
the only good modern vegetable source is flax seed; however, some
nuts, such as walnuts, and a few oils, such as canola oil, are
helpful. Omega-3 oils have a significant role in preventing inflammatory
diseases (e.g., rheumatoid arthritis, Crohns disease) and
heart disease. I put a tablespoon of flax oil on my daily bowl
of high fiber cereal that I eat with soy beverage to increase
my antioxidantsits an inexpensive, preventive, daily
ritual supported by a very large body of research.
Its About Antioxidants
When we say damage is caused by oxidation, we could use the modern
buzzwords, free radicals. These are atoms or molecules in a stage
where an electron is "free" to link to an oxygen atom.
Every oxidative process, from rust to lung cancer and a lit match,
has a free radical as its very earliest step. Think of a free
radical reaction as a miniature explosion that occurs in nanoseconds.
Visualize the antioxidants as nature's demolition teams that neutralize
the free radicals before they can do any damage.
Although free radicals are the cost of breathing oxygen, nature
seems to have anticipated the problem and provides an abundance
of protective antioxidants. Fruits, vegetables, grains, and cereals
are rich in the antioxidants.
The chart shows graphically the
relative antioxidant delivery of some common foods. An excellent,
no brainer way to start any day is a whole-grain,
high-fiber cereal topped with blueberries (frozen is fine), soy
beverage, and a tablespoon of flax oil, a glass of orange juice
(vitamin C), and half a grapefruit (more vitamin C) or other fruit.
Eat lots of fruits and vegetables during the day. When you choose
wine, make it a red wine, as it has most of the antioxidants found
in red grapes.
Color on Your Plate
An old wives tale teaches that we should always
have color (vegetables) on our plate. This teaching, which I traced
to the 15th century, focused on the prevention of cancer, but
it also guaranteed adequate vitamin A, which is responsible for
general tissue health, night vision, and healthy eye tissue, especially
the cornea. Indeed, most blindness in second- and third-world
countries occurs because children dont get sufficient daily
amounts of vitamin A, as beta-carotene, from even a small carrot.
Think of this: the cost of a single cruise missile could prevent
all that blindness with some money left over. The simplest, most
healthful snack available is baby carrots, which are readily available
in small packs in supermarkets, food outlets, and even airports.
About The Author
Jim Scala is a member of EAS and is the president of the Mt. Diablo
Astronomical Society. He is a biochemist with degrees from Columbia
(B.A.) and Cornell (Ph.D.) Universities, and post-doctoral studies
at Harvard University. In addition to research and teaching, he
is the author of 14 books on nutrition. With that career coming
to a close, he passionately pursues astronomy, especially CCD
astronomy, from his backyard observatory in Lafayette. He welcomes
visitors to the La Scala observatory.