do crt damage your eyesight?

[yhelothar]

So even it was at 10Hz, and your eyes can focus 10 times a second, why would it need to refocus anyways? The glass is still the same distance whether or not there is an image displayed on it..
I don't get eyestrain at all looking at CRTs, but I do if the CRT is at 60Hz.

 

[VIAN]

Your eyes subconciously are constantly in and out of focus when you look at a CRT monitor, because the image isnt constantly on the monitor.

If you are talking about your eyes adjusting to the light. That process is so slow, that I really don't think it would matter, especially at 85Hz or above where flickering is unnoticeable. Wake up in the middle of the night and go to your monitor, it will take a minute or longer for your eyes to adjust to the light. And that's because of the difference between dark and light, if you don't see the flicker, there is no difference, so no adjusting, or if any so little that it would be negligible. Pay attention to your body, it explains a lot.

I am actually going to comment more on the eye issuse. Maybe our eyes cant go in and out of focus 100 times a second, however they are trying as best as they can to keep up. Maybe thats what causes eyestrain.

Not at 85Hz. If you don't see flicker then, that means that they aren't, just at below 85. You are right that at 60Hz, that is why your eyes get damaged, but at 85Hz, it doesn't happen anymore.

 

[Johnbear007]

Originally posted by: jim1976
I'm no expert at this but IMO if you care for your eyes go for LCD.
That of course is an issue if you spend a lot of time in front of your screen.
After so many yrs in front of my CRTs I finally start to realize that my eyesight is not what it used to be. I've never had any headaches though even after hrs of gaming.That said I always try to use 100Hz and with a light on of course at nights.
But when I use a friend's LCD I can feel that my eyes are safe in front of such a screen.

After so many yrs in front of my CRTs I finally start to realize that my eyesight is not what it used to be.

Hmmmmm lets be a good little scientist and understand the concept of correlation and factors untested for.

If you have been sitting in front of a computer for serveral years the degradation in eyesight is as likely as explainable, if not more so, by the years that have passed, and not by the monitor.

 

[Navid]

I thought that there was some material (Phosphorous?) on the monitor screen that kept the light for some time. So, even though every pixel is updated periodically and for very short time, it does not really turn on and off.

You talk about a single dot moving on the screen. That made me think and wonder!

 

[VIAN]

you're right, plus our eyes keep some light also, giving the full light all at once, but changing the picture little by little. It happens so fast anway that we perceive it as a full pic every time.

 

[MadOni0n]

great thread, learning alot.

 

[reallyscrued]

(at first glance of the title)

does sitting on the toilet hurt ur ass?

 

[chadomaly]

"after so many years looking at CRT my eyesight isn't what it was"

It's probably the years, not the CRT that makes your eyes worse 😛

 

[Tab]

Originally posted by: VIAN

Your eyes subconciously are constantly in and out of focus when you look at a CRT monitor, because the image isnt constantly on the monitor.

If you are talking about your eyes adjusting to the light. That process is so slow, that I really don't think it would matter, especially at 85Hz or above where flickering is unnoticeable. Wake up in the middle of the night and go to your monitor, it will take a minute or longer for your eyes to adjust to the light. And that's because of the difference between dark and light, if you don't see the flicker, there is no difference, so no adjusting, or if any so little that it would be negligible. Pay attention to your body, it explains a lot.

So how come we don't have insanely high refresh rate then VIAN? There is always a flicker its just not as noticable.

Originally posted by: VIAN

I am actually going to comment more on the eye issuse. Maybe our eyes cant go in and out of focus 100 times a second, however they are trying as best as they can to keep up. Maybe thats what causes eyestrain.

Not at 85Hz. If you don't see flicker then, that means that they aren't, just at below 85. You are right that at 60Hz, that is why your eyes get damaged, but at 85Hz, it doesn't happen anymore.

Not a 85Hz? Are all of our eyes programmed to look at a CRT at 85hz? No they aren't. The image is still and always flickering. I don't really know how to completely answer this, but your eyes are still going in a out of focus reguardless of the refresh rate.

you're right, plus our eyes keep some light also, giving the full light all at once, but changing the picture little by little. It happens so fast anway that we perceive it as a full pic every time.

Our eyes keep light? Prove it. How could our eyes keep light?

 

[VIAN]

So how come we don't have insanely high refresh rate then VIAN? There is always a flicker its just not as noticable.

I don't understand what you are trying to say.

I looked it up and phosphors glow for at max 1ms in good monitors. So it only stays a glow for 1 out of 1000fps meaning that there is a flicker.

So I agree with you that there is a flicker. Although, the flicker is for the most part very difficult to find if it's able to be found. I would suggest the opposite of looking closely at the screen. Looking about 2 feet away, you can see that the picture is weird, I can't explain what I see, but the picture doesn't seem completely concrete.

Our eyes keep light? Prove it. How could our eyes keep light?

You eyes or your mind retains an after glow of light. Everyone knows that. That's how 24fps is able to blur into motion.

I agree that an LCD is better for your eyes, but the quality of the LCD would probably matter too, for the clearness of the picture. Digital is recommended.

 

[MadOni0n]

So is the L70S a solid choice?

 

[VIAN]

I would get one with a digital connection.

You know what really pisses me off, why don't they make 15" monitors with 16ms response and DVI input at the same time. WTF is up with that.:|

 

[yhelothar]

your eyes are still going in a out of focus reguardless of the refresh rate.

You still haven't explained why the eye would go in and out of focus... :roll:
You still haven't found any source backing up this obviously bs claim.

 

[VIAN]

You still haven't explained why the eye would go in and out of focus...
You still haven't found any source backing up this obviously bs claim.

He isn't talking about depth focus. He is talking about light focus.

When there is little ambient light, your pupils get larger. When there is much ambient light your pupils get smaller. With the refresh rate, there is flicker, meaning your pupils are always getting smaller and getting bigger contiunously, stressing out your eyes.

 

[yhelothar]

Well good, you already proved him wrong on the light focus anyways...

 

[Noid]

Originally posted by: VIAN

You still haven't explained why the eye would go in and out of focus...
You still haven't found any source backing up this obviously bs claim.

He isn't talking about depth focus. He is talking about light focus.

When there is little ambient light, your pupils get larger. When there is much ambient light your pupils get smaller. With the refresh rate, there is flicker, meaning your pupils are always getting smaller and getting bigger contiunously, stressing out your eyes.

This thread is getting funny ... 😛
(no offense)

I'm not willing to 'google' the truth here ...

All of you amature optometrists are crakn me up.

 

[Noid]

OK ... I lied ...

WebMD

(look for title "Do Computers Damage the Eyes?" )
(since some of you cant read ,,, hehe

"WebMD hopes that you can put this information to good use"

 

[Tab]

All of you amature optometrists are crakn me up.

I guess you'd fit into the group as well?

Or, What is computer vision syndrome, and how do I avoid it?

Do computers cause vision damage?



Answer:

Computers represent the number-one source for workplace discomfort, but their use does not harm the visual pathway.

Vision is a passive phenomenon. Looking at the screen will not harm the eye or alter its refractive power.

Having said that, spending ALL DAY in front of a monitor can induce eyestrain or eye fatigue, dry eyes, burning eyes, light sensitivity, blurred vision, headaches and pain in the shoulders, neck or back.

Here are some proven steps that can help you avoid computer vision syndrome, and make you more comfortable at the workstation:

Turn off lights adjacent to the monitor or behind the computer. Illumination from behind the operator works best.
The desktop should be 29 inches from the ground.
Do not use a wrist rest for either the keyboard or the mouse.
Position the monitor and/or chair height so that when LOOKING STRAIGHT AT THE MONITOR your line of sight is directly at the top edge of the screen. This generates a slight downward gaze - most comfortable for long work periods.
Finally, the screen surface should be approximately 30 inches from your face in order that the intermediate portion of your trifocals focus properly without requiring excess accommodation from you.

1)They arent even talking about any specific monitor. I think if my eyes hurt, something isnt right... I need to go hunt down a optimistrisct(sp?)

You still haven't explained why the eye would go in and out of focus...

Okay, you're eyes are constantly going in a out of focus because the image your eyes are focusing on isn't really there constantly. Now I explained it 🙂

You still haven't found any source backing up this obviously bs claim.

How is it obiviously bs? You havent proved me wrong either. You're the one claiming I am infact wrong, so prove it.

 

[Noid]

Originally posted by: Tabb

All of you amature optometrists are crakn me up.

I guess you'd fit into the group as well?

No ,,, I dont ,,, because I'm not 'speculating' on this matter.
(I know better,,, that's why I attempted to guide you 'speculators' in the right direction)

Both my posts are factual.

speculate

 

[Tab]

Originally posted by: Noid

Originally posted by: Tabb

All of you amature optometrists are crakn me up.

I guess you'd fit into the group as well?

No ,,, I dont ,,, because I'm not 'speculating' on this matter.
(I know better,,, that's why I attempted to guide you 'speculators' in the right direction)

Both my posts are factual.

speculate

My posts aren't factual? Prove it.

 

[VIAN]

So I went to COMPUSA today to look at some LCDs.

It should be very difficult to notice the difference between an LCD and a CRT at least 100Hz.

Going from 100Hz to 85Hz, I notice a bit of discomfort that is difficult to point out. Going from 120Hz to 100Hz, nothing was noticed.

I looked at LCDs from various manufacturers.

These are my conclusions of what the differences are between LCD and CRTs:

LCDs Pros:
Much clearer picture, requires DVI input and dependent on model
Much sharper picture, ideal for text
Takes up much less space
Uses up much less power
Less noticeable tearing with Vsync disabled

CRTs(AG) Pros:
Color is much better
Response time is much better, ideal for games
Much cheaper
Contrast is much better than certain LCD models
Viewing angles are much better than certain LCD models
Dead or malfunctioning pixels are non-existant

 

[Tab]

You set CRTs monitors at CompUSA at 100-120Hz? :|

 

[ronnn]

I wish this thread would stop. I have now found myself worrying about my eyes and pricing 19" lcds. My spending and excuses never end. 😱

 

[VIAN]

You set CRTs monitors at CompUSA at 100-120Hz?

No, I'm comparing it to my CRT, which isn't the best of them all, but it isn't cheap either.

 

[Tab]

Originally posted by: VIAN

You set CRTs monitors at CompUSA at 100-120Hz?

No, I'm comparing it to my CRT, which isn't the best of them all, but it isn't cheap either.

What do you have?