Tuesday, December 16, 2008

vision

So many meanings contained in one little word "vision." We may use it to refer to the act of seeing, the physical quality of sight ("does she have good vision?"). We may also mean the things one sees, both the manifest which we see with our eyes ("she was a vision in white") and the not yet manifest, which we see in our minds ("he had a vision that foretold the future"). Too, we may mean a quality of character possessed by a person ("he has vision"), that they have insight, greater perceptiveness, lofty goals, and a clear mission.

We use the words related to vision in so many different ways as well. "I see" may mean that we perceive some physical thing in front of us, or that we believe we understand or comprehend something.

When I was young and very silly, I romanticized physical blindness. The play/movie "The Miracle Worker" (Anne Bancroft and Patty Duke) was so dramatic and inspiring. I mistakenly believed that what made Helen Keller special was her blindness and deafness, not recognizing that many people have been blind and deaf, who did not share in the special spirit that made Helen Keller the hero that she is. Helen Keller's specialness came from her vision (insight, perceptiveness, goals and mission), not her lack of seeing.

Even as I romanticized blindness (learning Braille for example), I took the physical ability to see for granted. True, I had poor eye sight, and had to get glasses by the age of 10. But I always assumed that technology could compensate for any vision problems I had. My cavalier attitude towards my vision ended abruptly four and a half years ago, when I got a tear in my left retina, and learned how fragile the human eye and human sight really is. Now the same thing is threatening to happen again, and there is very little to do but wait and watch, and seek help immediately if a tear or detachment occur.

Human eyes are far from perfect mechanisms. Some human eyeballs are too short, resulting in far sightedness, and other human eyeballs are too long, resulting in nearsightedness (myopia). Most people know these basics, and know that both nearsightedness and farsightedness can be corrected with glasses or contact lenses, or even with surgery like Lasik.

What few people realize is that extreme myopia or nearsightedness places one at greater risk for blindness from retinal detachment. Here is what the Mayo Clinic has to say on the subject:
If you're significantly nearsighted, it's possible that the retina of your eye is thin. The thinner your retina, the higher your risk of developing a retinal tear or retinal detachment. If you experience a sudden onset of flashes, floaters or a dark curtain or shadow across part of your eye, seek medical assistance immediately. Retinal detachment is a medical emergency, and time is critical. Unless the detached retina is promptly surgically reattached, this condition can cause permanent loss of vision in the affected eye.


The greatest risk for retinal tear and retinal detachment among the severely myopic comes in the fifties and sixties. Part of the normal process of aging causes the interior vitreous jell that fills the eye to contract and shrink away from the outer edges. This by itself has little impact on our sight, but for those with thin retinas, the pulling away of this interior fluid can have just enough force to cause a tear or hole in the retina. The tear or hole becomes a place where the fluid of the eye can seep between the retina and the wall of the eye, pushing the retina loose, causing it to detach.

Warning signs of a retinal tear or hole that almost always precede retinal detachment include:
  • The sudden appearance of many floaters — small bits of debris in your field of vision that look like spots, hairs or strings and seem to float before your eyes
  • Sudden flashes of light in one or both eyes.
Retinal detachment itself has very obvious symptoms:
  • A shadow or curtain over a portion of your visual field
  • A sudden blur in your vision

So take heed. Although the greatest risk is to people with severe myopia (nearsightedness) who are in middle age, retinal tears and retinal detachment can occur to anyone at any age. Immediate, emergency eye surgery can repair both retinal tear (making retinal detachment less likely), and can usually (but not always) reattach a detached retina especially if caught within hours.

4 comments:

fourwindshaiga said...

Sue, this was very interesting. My husband just found out he had a wrinkle in his retina. And, he has been seeing floaters for quite a while.

Sue said...

sandy, best wishes and good thoughts to your husband, hopefully his retina situation will remain benign and not result in a detachment. I had a tear in left eye in 2004, and had laser surgery immediately to "stitch" it down -- not a problem since. Right now, the doctor merely says that there is "activity" (the vitreous jell pulling away from the retina) in my right eye and that I must be vigilent for signs any indication that the movement has created a new tear in that eye. Since any kind of living or moving of heavy objects (more than 20 lbs) is forbidden, it gives me a good excuse not to do housework, and to get my husband to tote all the garbage and laundry. He,he! There is always an upside!

Jim said...

Hi Sue -- Vision is precious to me. Every male in my lineage was blind before he died. Some of the women cousins also became blind.
As far as I know they all had macro degeneration, the slow kind. Dad had one eye where the retna detached and was lost that way.
I figure that I have ten to fifteen more years of fairly good sight remaining.
..

Sue said...

Jim -- being aware of the fragility of sight certainly makes me even more appreciative of the world around me. Going to store up all the images and sights I possibly can!