Everyone Loves their OD, Even Justin Timberlake!

Everyone Loves their OD, Even Justin Timberlake!

I’m a fan of JT and it looks like his is a fan of his Eye Doctor! When I saw this I couldn’t resist writing a blog about 20/20 vision! Just what exactly does 20/20 vision mean?

Visual acuity is usually measured with a Snellen chart.

The expression “20/20″ is so common in the United States that there’s even a TV show named after it. But what does it really mean? Here’s where the 20/20 designation comes from.

By looking at lots of people, Optometrists have established what a “normal” or average human being should be able to see when standing 20 feet away from an eye chart. If you have 20/20 vision, it means that when you stand 20 feet away from the chart you can see what the “normal” human being can see. (In metric, the standard is 6 meters and it’s called 6/6 vision). In other words, your vision is “normal” — most people can see what you see at 20 feet.

If you have 20/40 vision, it means that when you stand 20 feet away from the chart you can see what an average human can see when standing 40 feet from the chart. To further clarify: if there is a person with “normal” vision standing 40 feet away from the chart and you are standing only 20 feet away from it, you both can see the same detail. 20/100 means that when you stand 20 feet from the chart you can see what a person with “normal” vision standing 100 feet away can see. 20/200 is the cutoff for legal blindness in the United States.

You can also have vision that is better than the norm, which is stated in the opposite ratio. A person with 20/10 vision can see at 20 feet what a person with “normal” vision can see at 10 feet.

Levels of Vision

20/20 – Normal vision. Fighter pilot minimum. Required to read the stock quotes in the newspaper, or numbers in the telephone book.
20/40 – Able to pass Driver’s License Test in all 50 States. Most printed material is at this level.
20/80 – Able to read alarm clock at 10 feet. News Headlines are this size.
20/200 – Legal blindness. Able to see STOP sign letters.

So all this leads me to ask…Is JT saying is new CD is a “Normal” or “Average” Experience???

Next Posting: What the heck is that thing in front of JT’s face and what does it do??

Could Aspirin Increase the Risk of Age-Related Macular Degeneration?

Say it ain’t so! Could it be that our miracle cure-all can contribute to age-related vision loss when taking regularly?

A new study published in the JAMA Internal Medicine suggests that there could be a link between regular aspirin use and an increased risk of developing the more severe “wet” form of age-related macular degeneration; even when smoking and heart disease risks are taken into account. The researchers found that the relationship was “dose-dependent” (the more aspirin a person took on a regular basis, the higher the risk of the vision loss condition).

Age-related macular degeneration (the leading cause of blindness among people over the age of 55), is a condition that occurs when the retina begins to degenerate. It is characterized by loss of sight in the center of the field of vision.  There are two main types of macular degeneration: Dry (more common) and wet (which is rarer but more severe). Wet age-related macular degeneration occurs when blood vessels leak into the macula (which is located in the middle of the retina), thereby blocking vision.

The study which was conducted by University of Sydney researchers included 2,389 people whose aspirin habits and vision loss were tracked over 15 years (via four examinations). Of those people, 257 (or 10.8 percent) regularly took aspirin; however, researchers didn’t provide full information on why these people took the aspirin.

By the end of the 15 year study period, 24.5 percent of the study participants had developed “wet” age-related macular degeneration. The researchers’ discovered that a greater proportion of regular aspirin users had the disease than the aspirin non-users.

Even in light of the results, the researchers did not feel that the evidence was strong enough to suggest people stop regular aspirin use, though some who may be at an increased risk for age-related macular degeneration might want to talk to their doctors about their risks.

This is not the first study to show a link between regular aspirin use and macular degeneration. A study published last year in the Journal of the American Medical Association showed that regularly taking aspirin for a decade is linked with an increased risk of developing the eye disease.

Another study, published in 2011 in the journal Ophthalmology, showed that people who take aspirin twice a day have a fifty percent greater risk of advanced age-related macular degeneration, compared with people who don’t regularly take aspirin. However, even that risk is still relatively low.

So what does it all mean?? Who knows! I will continue to take aspirin as needed, but I do think it is something to keep an eye on (pun intended)!

To read original article click here: https://www.huffingtonpost.com/2013/01/22/aspirin-macular-degeneration-age-related_n_2527221.html

How Many Blinks Are Enough?

“How many blinks are enough to keep your eyes moist and prevent eye strain?”  This is a question I get fairly often in my practice.  A low blink rate can cause irritated eyes (“eye strain”). Small fonts and poor type contrast, can contribute to low blink rates.  But the good news is eye strain is not permanent.

Some people believe that they could be “hurting” or “damaging” their eyes by using small type on their computer screens. However, Dr. Kimberly Yen, assistant professor of ophthalmology at Baylor College of Medicine states:

 “Despite popular belief, sitting too close to the television, or in this case the computer, won’t cause blindness or other permanent damage, what it can do is cause eye strain symptoms.”

When eyes are focused on one item for a long period of time, whether it’s a computer screen, television or even a book, the blink rate slows. That could lead to eyes feeling dry or uncomfortable. Vision could even begin to blur or double. One common side effect of eye strain is headache.

source: Baylor College of Medicine

There is an interesting article in Eye Magazine that breaks down specific stressful conditions for one’s eyes:

  • reading small text sizes
  • reading low-contrast gray text
  • reading with a light source behind the reading material to cause glare
  • reading from too close a distance, which causes the eyes to point inward towards each other (convergence stress)
  • reading from variable focal distances (accommodative stress)
  • reading while wearing glasses that simulate an astigmatism (refractive stress)

“Small text sizes, low contrast, glare and refractive stress all resulted in increased activity in the orbicularis oculi, while convergence stress and accommodative stress did not, though after reading in these two conditions, readers are more likely to report headaches and pain coming from behind the eye. Stressors such as small text size and glare are reported as irritation on the front of the eye.”

They conclude that the blink rate is a key factor in eye stress. Difficult-to-read text (e.g. small text) causes a lower blink rate.  They go on to add:

“Light grey text on a white background and small text size both lead to an increased orbicularis oculi activity and decreased blinking. These two conditions are related to text quality, and we would expect to find similar indicators of eye fatigue with poor font quality or condensed letter spacing. To reduce this type of eye strain, we need text of the highest possible quality.

…other studies found that we blink far more often under relaxed conditions than while reading: 22 blinks per minute while relaxed, versus ten blinks per minute while reading a book. A recent study at Pacific University illuminated why blinking is suppressed during reading. Tai and Sheedy found that the eye movement following a blink was far more likely to be a regressive or backward corrective eye movement than one that did not follow a blink.”

My advice is to bump up the size of the font that you are reading anytime you start to feels the symptoms of eye strain. Since it is not a permanent condition, you should experience relief in a short amount of time.