Question for Jim Bradley

I just walked into the house to use the facilities and fill my glass and noticed my 6 year old grand daughter was watching cartoons and sitting about 3 feet from the TV. My first thought was to make her move back since I have been taught from the time I was not much older then her that this was bad for the eye. Now tell me sir is there any really scientific basis for this or is it an old wives tale.

Hi Don,

The answer is "Yes" and "No."

Back in the 1940s and 1950s there was hard radiation from the TV picture tube. It was a contributing factor to the development of cataracts among other things. Radiation (including light) drops off at the inverse square law. Every time you double the distance, you have one forth the radiation. Therefore moving back from the TV was a very good thing to do.

However, for a lot of years that factor has been eliminated by the materials in the picture tube glass. The frontal radiation has dropped to zero for all practical purposes. So, as far as radiation is concerned, it does not matter where you sit in front of the TV set.

All young children sit close to the TV. I don't know why, but they do. It would be nice to have a few bucks for every time a parent has asked me if their child has bad eyes because they sit so close. Or if sitting close is going to cause bad eyes. Gee, I could have a new fancy Delta TS or a SawStop with that kind of dinero.

If you have any further questions, do not hesitate to ask.

You notice that I said that illumination drops off on the inverse square law. That means you have one forth the amount of light if you are eight feet from the light bulb than you would have at four feet. This is the reason supplemental illumination is a very good thing. That lamp hanging on your BS or DP is there for a very good reason.

As long as I am talking about luminaires and lamps, let me take another minute of your time. Tubular lamps, like 4 ft or 8 ft fluorescents, are a good source of shop illumination. A tube lamp pretty much does not cast a shadow to be a problem when you use spinny things or pointy things. Then when you add supplemental lighting to your task to kick up the candle power you see even better.

Enjoy,

Jim

My mom was right

Thanks Jim...

(But I'm still gonna tell my kids to back up!)

I just heard a report on TV the other day that these new 3D TVs can cause issue with young children if the watch it for more then a couple of hours a day. They said it was because children eyes are still growing. All I really know is that these 3D TVs and movies give me a head ache.

If you get a headache from 3-D pictures you probably have an eye coordination problem.

For you look-it-up people try:
Esophoria
Exophoria
Stereopsis
Depth perception

Most of the eye coordination problems that would cause this are easily corrected by some simple eye exercises you can do at home. The great majority of the time the exercises are quite simple and do not require any special equipment or office visits to the optometrist. Therefore the correction usually does not cost money---just time.

If totally corrected, you will probably stay that way because your eyes will have found a much easier way to work and good old human laziness will encourage them to work the new way. (That sentence would never get through a grammar checker. You would get a message like, "That sentence contains a bazillion words. Try to break it down into shorter sentences.").

Frequently people with this type of problem have some of the following symptoms: Skip words when reading, Repeat words when reading, Get upset stomach if tries to read in the car, Seasickness, Difficulty hitting or catching a ball. Some of the people will have only one or two of these symptoms while some people may have five or six of them...or some other symptom not mentioned.

Treating the problem is a sub-specialty of optometry or sometimes ophthalmology. Usually your best bet is to hit the Yellow Pages under "Optometrists" and look for some one who does eye exercises...perhaps they will say vision training or visual training. BEWARE there are a fair amount of people who are NOT doctors who do "Eye Exercises." There is no way that they can have a grasp on this subject, there are too many factors to learn. The docs pick up the info over 4 years of training including time in therapy clinics. There are not only special classes on the subject, but the subject is referred to in many other classes such as optics, neurology, pathology, etc.

Sorry. When I get off on a subject, I frequently forget to turn off my mouth.

Enjoy,

Jim