Naked Science Forum
On the Lighter Side => That CAN'T be true! => Topic started by: paul.fr on 07/09/2007 12:39:05
-
i was always told this, but is it true?
-
It will strain your eyes , which will then lead to a possible head ache but I do not believe it will actually do harm......this is what I was told once anyway.
-
It will not make your eyesight any worse?
-
I don't know that I'm convinced byt the argument it won't make your eyesight worse. A trainee optopmetrist friend told me recently that there's a good deal of scope, as an optician, for being horribly sued for permanently damaging someone's eyesight by not setting their glasses up right and thus causing strain to the muscles which control the direction your eyes point in. In exreme cases this can stop the eyes working together properly to provide binocular vision.
Given how much of the time people wear their specs for compared to watching telly, probably the risks are much lower, but it seems like a theoretical possibility from my underinformed perspective.
-
Sue the optician? Surely, anyone with half a brain would take their glasses off if their eyes were getting sore. If it's persistent then take the glasses back & get them checked.
If your binocular vision fails as a result of continually wearing glasses that make your eyes hurt, then who is to blame?
It would be interesting to see if anyone charged with a driving offence could use a "the optician made my glasses wrong" defence. I think the judge would send them to prison for being grossly stupid!
-
LOL!!
-
A trainee optopmetrist friend told me recently that there's a good deal of scope, as an optician, for being horribly sued for permanently damaging someone's eyesight by not setting their glasses up right and thus causing strain to the muscles which control the direction your eyes point in. In exreme cases this can stop the eyes working together properly to provide binocular vision.
ormed perspective.
That said, the experience of my friends and family is that opticians make mistakes far too often for comfort. Transposing the measurements for the left and right eyes on the form seems to be one easy mistake.
I'm not an optician, but a (conventional) cathode-ray tube picture is not particularly sharp, so I imagine that could cause eyestrain if your eyes are trying to hard to focus on something inherently fuzzy. Watching from a distance you'll probably focus equally on the surround of the set - and at longer distances the focussing muscles in the eye are more relaxed anyway.
Another consideration is that (conventional) TVs flicker at 50Hz. Peripheral vision is more sensitive to flicker so if you sit very close you're more likely to perceive the flicker and maybe suffer headaches/stress etc.
Modern over-compressed digital TV looks awful if you look too closely anyway. ;-)
Interesting trick: try watching TV with your head upside-down (look through your legs of something)... it appears much more flickery. I haven't seen this mentioned in scientific literature, but I assume the ever-adaptable brain learns to filter out top-to-bottom flicker (normal flicker) but still remains more sensitive to bottom-to-top flicker!
-
well watching TV in first place is bad for your eyes, but I dont belive that sitting closer will effect you eye sight more or less, unless you are talking about 2 feet away, and 20 yards away, I belive that would make a small difference.
-
What about consantly sitting in front of a computer (laptop or desktop) or reading in the dark. Would these have similar effects?
-
What about consantly sitting in front of a computer (laptop or desktop) or reading in the dark. Would these have similar effects?
There are lots of variables.
Firstly, most of the stories about TV's causing problems with eyesight were in the days when all TV's used CRTs. I would suggest that LCD and other technologies would have a very different set of issues (if issues there be).
I have always found CRT's to be tiring to use, and since I first saw the first LCD screen around 1990, I have been looking forward to their becoming mainstream; which ofcourse they now are.