A Sabbatical…Of Sorts

May 12, 2009

Thank you to all who have visited this site. I have been overwhelmed with the number of people that have looked over the site and who have an interest in our amazing visual system. November 2008 was a record for The Amazing Eye — 1,174 visits!

As you can tell I’ve taken a sabbatical from the blog to work on my new blog called The Seeing Eye Blog. It’s purpose is very different from The Amazing Eye. It is to aid entrepreneurs and small business owners to create an atmosphere of customer service. I know — it’s not even a distant third cousin thrice removed from the purpose of The Amazing Eye. However, I’ve felt that it’s intent of treating customer as they should be treated is of greater urgency and importance.

Explaining the amazing human visual system is facinating, but transforming businesses and people is essential.


Study Shows Eyeglasses Raise Kids Intellegence, Honesty

May 29, 2008

I remember getting my first pair of glasses at 14 years old. When my optometrist recommended them, visions of being called “four-eyes” and random punchings by the many prominent bullies at my school filled my mind. To make things worse, just a few months after getting my glasses, my orthodontist recommended braces! A very traumatic childhood indeed.

Research to the rescue! Kids may have a few less social problems to worry about in light of a new study.1 42 girls and 38 boys were shown various pairs of pictures of children, which included one child with glasses and the other without. About two thirds said the children wearing the glasses looked smarter and 57 percent said they looked more honest.

In my personal and professional opinion, children are not very interested in looking smarter or more honest when I tell them they need glasses. Kids mostly just want to fit into social circles with their peers. This is where the study results get interesting. Despite a child’s social fears with glasses, the researchers did not find any significant preference in who they’d rather play with, who looked better at sports, who looked more shy, nor who was better looking.

In the exam room, I find that girls tend to be more accepting of glasses. In fact, occasionally I’ll exam a child that attempts to trick me into thinking they need glasses. These children are almost exclusively female between seven and 13 years old and later admit that one of their friends just got glasses. They squint and strain to make out the biggest “E” I have despite the computer analysis of their eyes showing they have little or no need for corrective lenses. As a doctor, I can’t just assume the child is not being truthful. So after a battery of tests to verify eye health and by using some tricks of the trade to ensure good visual performance, I notify the parent in private without embarrassing the child. Hey, it’s rough being a kid these days.

References

1. http://www.healthday.com/Article.asp?AID=615522


One-sided World; Bizarre Brain Injury

May 14, 2008

Imagine half of your world disappearing before your eyes in a split second. You wait for it to come back, but it never does. Everything you see is cut in half! I recently met a man that experienced this odd and rare brain condition.

This senior-aged man arrived in our practice in a wheelchair saying that he couldn’t see to his left. He had recently suffered a stroke in the right half of his brain and had lost complete function of his left arm and leg. After some testing, we discovered that indeed the entire left side of his vision was gone due to the stroke. This made sense since the right brain receives left side vision information.

However, I wasn’t expecting what he said next, “I have to turn my plate around to see the food on the other side.” You see, if just the left side of his vision is missing all he’d have to do is look a little more to his left to see the other side of the plate. I diagnosed him with hemispatial neglect (AKA left side neglect). He’s only aware of the right side of objects!

Patients with this condition will eat only the food on the right side of their plate, notice only the right side of a picture, and only draw the right side of a clock. This is an actual drawing from a hemispatial neglect patient. Some severe cases have even demonstrated the amazing ability to flip the neglect in their mind’s eye. For example, after being shown an upside-down picture of a face, the patient will mentally flip the picture right-side up and neglect the left side of the face!

We learn a lot about brain function by studying the devastating, but fascinating effects of brain damage. From neglect patients we’ve discovered that the right side of the brain is responsible for spatial interpretation. The eyes collect data about our environment, but the brain interprets and organizes it.


Ancient Illusions; It’s All Greek To Me

April 24, 2008

I recently watched a well-done documentary on the architectural marvel, the Parthenon. Feel free to watch the whole program on PBS’s website. If you do, you can skip this post, because I’ll paraphrase just a part of the documentary here that deals with illusions.

As you can see from a close look at this picture, the columns are made up of multiple stacked “drums.” Recently, while the Acropolis Restoration Project was attempting to rebuild the 46 columns, it was discovered that the drums had very slightly different diameters. This finding suggested that the columns were not straight, but were curved (wider at the bottom). In fact, very few of the parts of the temple had a straight line to it, even the foundation was “bowed.”

Amazingly, it was determined that the ancient Greeks were aware of optical illusions and used them in the architecture of the Parthenon. The building was a tribute to the goddess Athena and was built to be a symbol of perfection. They realized they must use optical illusions to create a temple that appeared perfect. You could even say that they incorporated optical “refinements” rather than illusions. The intended purpose of these refinements has still not been determined. Many believe they give a lifeless edifice an appearance of a living and breathing creation.


Visual Auto-Completion

April 7, 2008

Have you ever had the annoyance of typing away on your word processor and had it automatically “correct” something you knew was already correct? My favorite is when I type “i.e.” and it thinks I meant to type “I.e.” Your computer thinks it’s smarter than you are. I’d like to think I’m smarter than it.

Your brain also has a built-in auto-completion or auto-correction function. And just like your word processor it often auto-corrects correctly and sometimes not. Here’s an example when it guesses incorrectly.

Most people say that they can see a white triangle. Your brain tries to complete the alignment of the individual shapes. If you look closely you may even “see” faint lines that make up the perceived white triangle. However, there are no lines. In fact, there is no triangle.

An example of when the brain correctly auto-corrects is when it conceals the blind spot in our vision. This blind spot is formed when 1.5 million tiny nerves from our retina squeeze together and exit out the back of our eyes on their way to the brain. There are no light receiving cells in this part of the retina. In other words, we should see a small black hole to each side of our vision, but we don’t, compliments of the brain’s auto-correction feature.

Want to find your blind spot?

  1. Cover your left eye with your left hand. (Make sure you can’t see through your fingers.)
  2. Hold your right thumb up at arms length directly in front of you.
  3. Look directly at your thumbnail. Without moving your eye from that position, slowly move your thumb slightly to your right about 8-10 inches.
  4. You should notice that your thumbnail suddenly disappears.

Congratulations! Your vision has now been auto-corrected.


You Too Can Be Legally Blind for $5.99!

March 17, 2008

Well, at least you can experience legal blindness for next to nothing. We’ll get to that in a minute.

The recent news of a legally blind man becoming governor of New York has the world rethinking the capabilities of the blind. To recap the media coverage, Lt. Gov. David A. Paterson took over the office of the morally-blind Eliot Spitzer. Governor Paterson, as reported by the New York Times, is totally blind in his left eye and legally-blind in his right eye. He is reported to have 20/400 vision, which means he can barely see objects from 20 feet away what the average person can see 400 feet away.

All the media coverage is also dispelling myths regarding legal blindness. In this blog post I want to do my professional duty to de-mystify and demonstrate legal blindness.

The United States Congress says that if a person still sees 20/200 vision, or worse, after glasses and/or contacts, then they are legally blind. It also states that if someone has only 20 degrees of peripheral vision, or less, they are also considered legally blind.

The misunderstanding occurs when the average person confuses “total blindness” with “legal blindness.” Let’s give some examples.

river_orig_1.jpg

 

river_20_200.jpg

 

river_20_400.jpg

 

river_peripheral_1.jpg

As you can see, someone who is barely legally blind, as depicted above, is not even close to being totally blind. This explains why Gov. Paterson, with 20/400 vision, walks the hallways without assistance and can recognize faces at conversation distance. However, visual details and contrast are dramatically reduced, which limits these individuals in certain activities, such as driving and reading.

If you’ve ever wanted to experience 20/200 vision just visit your local pharmacy. Find a pair of reading glasses labeled with a power of +3.00 and put them on (that’s the $5.99 part), or if you already wear vision correction, put them on over your current glasses or contacts. Now look off in the distance. Instant 20/200 vision!

Want to try 20 degrees of peripheral vision? Fold a sheet of paper in half. Punch a half-hole in the middle of the crease with a standard hole punch so that when you unfold the paper you have a single circular hole. Now hold the paper about one inch away from your eye and look through the hole. Instant legal blindness!

In no way do I wish to diminish the severity of blindness. The achievements of these individuals is astounding, especially in a world that is designed for those of us with 20/20 vision.


We See Only What We Want to See

March 8, 2008

You may remember me talking about brain filtering; how our brain filters out what it doesn’t want to pay attention to. You could call it “selective sight”. For you married individuals out there, this is similar to “selective hearing” that plagues inattentive spouses. (I know I’m guilty of it.) I ran across some fun experiments that illustrate this phenomenon.

Simply put, the brain would get overloaded if it analyzed in detail everything we saw. Therefore, it ignores much of what the eyes see. Here’s a video I think you’ll find interesting.

The next video was shown to me in optometry school a few years ago. Play along and do the experiment yourself while watching the video. You’ll be amazed! Just click on this link. While watching the video, try to count the number of times the basketball is passed. Then watch it again, but this time just watch the video.


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