Wednesday, September 14, 2011

Why Do We Blink?

In my first year of optometry school, as part of the practical portion of our studies, we used to do vision screenings on kids in elementary schools around Boston. So picture me, the tall optometric freshman, kneeling down to examine the eyes of this adorable little 6 year old girl when she steps back and asks out loud "Harbir, why do we blink?". The whole classroom stopped and looked up at me...

I paused for a second, gathered as much information as I could from my 3 months of eye-related education, and began to answer. Well, cute little blonde-haired girl whose name I don't remember, there are 3 main reasons for blinking:

Number 1 is protection. Our eyelids and eyelashes provide a protective barrier against foreign objects such as dust, rocks, bits of metal, fruit flies, etc...

The second reason is lubrication. Every time we blink, our eyelids squeeze out small amounts of oil, water, and mucus to line the surface of the eye. Studies have shown that when we are engaged in activities that require more attention, we tend to blink less. That is why spending a lot of time on the computer can lead to dry eyes. So as soon as you're done reading this blog, get off the computer! Then come back and share it with all your friends :)

And last, but not least, the third reason for blinking is irrigation or removal of tears and waste. Our eyelids act similar to squeegees, the wonderful onomatopoeically named tool that helps smoothly remove water from car windows and such. Each time we blink, the lids pull tight and sweep tears and debris off the surface of the eye and towards the drainage duct which is located at the inner corner of the eye.

And that's why we blink.

Thursday, September 1, 2011

The Importance of Early Eye Exams for Kids

Since its back to school season, I thought it would be a good idea to write a little bit about childrens vision. I've been seeing a lot of kids in the past couple of weeks, most of whom are bright, young, happy, and healthy. Its actually kind of a fun experience for me. I get to hear a lot of interesting stories about their summertime activities. I find myself living vicariously through my young friends since I've spent most of my summer locked up in my dark exam room!
While most of the kids I see are returning for their annual check up, some are coming in to experience the fun and excitement of a Dr. Sian eye exam for the first time. Parents who are bringing their kids in for the first time will often ask me "When should my child have his/her first eye exam?". The answer is usually a bit surprising.

The American Optometric Association (AOA) and the Canadian Association of Optometrists (CAO) both agree that a child's first eye exam should be at 6 months of age. Of course, we don't expect the little munchkins to be able to read letters or even complain about blurry vision. But, it is vital at this age to make sure that the major structures of the eye are developing normally. One significant concern at this age is retinoblastoma, which is a tumor of the retina, the back surface of the eye. If caught early enough, it is possible to prevent the spread of the cancer to other parts of the body and, hopefully, save the affected eye.

A few years back there was a remarkable story of a person who detected a tumor in a baby's eye just by viewing photgraph and noticing that one of the pupils seemed to have a white reflection. This simple sign probably saved the baby's life.
Here's the story:

Interestingly enough, one of the tests we do on children, called the Bruckner test, actually mimics this same reflex seen with camera flashes. Simply by watching how light reflects off of the the retina, we can determine the general health of the eye, the shape of the eye (astigmatism), and a potential prescription for glasses (if necessary)


After 6 months, it is recommended that children have annual check ups to make sure everything is developing well.

In Canada, our health care system is based on prevention. In BC, Kids eye exams are free up to the age of 18. Regular check ups mean earlier detection and easier treatment.

Check Yearly, See Clearly!

If you have any questions or concerns, please don't hesitate to write to me or visit your friendly local optometrist :)

Also, take a peak at the following websites, they are very informative.

BCAO:
http://www.optometrists.bc.ca/code/navigate.aspx?Id=3
CAO:
http://www.opto.ca/en/parents/parents-corner.html
AOA: