Dangers of CRT Display

25 06 2008

// Well, this article is for those would are still using CRT(Cathode Ray Tube) monitor including me(i am currently using a Samsung SyncMaster 753s). Over the past few years, CRT have been used fewer and fewer in computers. Big companies like Dell, Macintosh, among others have stop the production of CRT displays. CRT displays are cheap but do you really know its dangers?

What is a CRT ?

The technology used in most televisions and computer display screens. A CRT works by moving an electron beam back and forth across the back of the screen. Each time the beam makes a pass across the screen, it lights up phosphor dots on the inside of the glass tube, thereby illuminating the active portions of the screen. By drawing many such lines from the top to the bottom of the screen, it creates an entire screenful of images (definition from webopedia).

The 5 Dangers of CRT (Computer Display)

1. Prolonged use of CRT cause nausea, vomiting, headache and confusion.

2. You can feel extremely tired due to electromagnetic radiation from CRT and can even suffer from memory loss, ringing in the ears and more.

3. Damage your eyes (cataracts, retina damage, eye cancer).

4. Illumination levels can strain and stress the eyes and reduce visual acuity.

5. Some of the larger or long term effects of electromagnetic radiation can include skin rash, nerve damage, joint pain, muscle spasms, digestive problems, blood cells which leak hemoglobin and brain tumors.

Reduce CRT effects of health

Here are some good practices which you must follows if you want to reduce the consequences :

1. Take mini breaks to focus on objects at various distances in the room.
2. Do figure 8 exercise with head letting the eyes change focus as the head moves.
3. Palming exercise – hold palms over eyes.

The palming exercise will teach you to relax your eyes, which in turn will bring healthy energy to your eyes.

First, rub your hands together until they feel warm (about 15 to 20 seconds). Then place your cupped hands over your closed eyes, being careful not to touch your eyes with the palms of your hands. The fingers of each hand should overlap and rest gently on the center of your forehead. Don’t create any unnecessary pressure on your face. If your arms get tired, rest your elbows on a table.

Sit quietly for one to two minutes with your hands over your eyes. The more relaxed you become, the blacker the darkness you will see with your eyes closed.

(More on eyes exercises below)

4. Ergonomics – Set up workstation so screen is level with eyes or at most 10″ down. Please note that bifocal wearers may need to lower monitor a couple of inches.
5. Make sure sunlight or bright lights are not directly behind you so there is no glare.  Better to be at the side.
6. Make sure the screen is not the only illumination in the room – turn on other lights or arrange for natural light.
7. Use a no glare screen

8. Adjust brightness and contrast to optimum comfort.

9. Tilt top of the monitor back 10 to 20 degrees.

Eyes Exercises

Eye Comfort Exercises

  1. Blinking (produces tears to help moisten and lubricate the eyes)
  2. Yawning (produces tears to help moisten and lubricate the eyes)
  3. Expose eyes to natural light


  1. while seated, brace elbows on the desk and close to the desk edge
  2. let weight fall forward
  3. cup hands over eyes
  4. close eyes
  5. inhale slowly through nose and hold for 4 seconds
  6. continue deep breathing for 15-30 seconds

Eye Movements

  1. close eyes
  2. slowly and gently move eyes up to the ceiling, then slowly down to the floor
  3. repeat 3 times
  4. close eyes
  5. slowly and gently move eyes to the left, then slowly to the right
  6. repeat 3 times

Focus Change

  1. hold one finger a few inches away form the eye
  2. focus on the finger
  3. slowly move the finger away
  4. focus far into the distance and then back to the finger
  5. slowly bring the finger back to within a few inches of the eye
  6. focus on something more than 8 feet away
  7. repeat 3 times

We know that our eyes are an important factor in all of our lives. We sometimes take sight for granted but can you imagine not being able to see everyday things normally. These little measures can help to keep your eyes healthy.




11 responses

3 08 2008


3 12 2008

I’ve been using a CRT monitor for over 4 years regularly and have experienced some of the symptoms you mentioned. Luckily, none of them where the serious ones. I’ve been planning on buying an LCD for a while primarily for the image clarity and resolutions they offer, but after reading this i’ll be more proactive at the idea.


10 06 2009

How many people out there have been damaged by CRT.
Without statistics, this is nothing but mere speculation.

Anyway, they say LCDs are safer but I know that, in time new dangers will be discovered.

I still believe that CRTs are less dangerous than shoes.

4 08 2009

Has any research been done regarding a connection between use of RADAR during the WW 2 and the onset of Alzheimer’s Disease in later life ??
My mother and her friend worked on Radar when they were in the WRAF.
Both developed Alzheimer’s.

23 09 2010

What a load of old tosh ! I have been using and repairing CRT TVs and monitors for tha lase 40 years and I have NEVER suffered an issues, LCDs are more dangerous ( bit too strong of a word) well LCD actually cause bad eye strain due to human eyes being able to pick up on the refreshing of the panel its self, this is a proven fact you brain does not actually see it so to put it but your eyes send this refreshing to the brain that does not really know what to do so sort of deletes it/ pretends not see it, symptoms raing from headach to dizzyness, to saw eyes, more apparent on older / dull screens !

CRTs if operated WITHOUT delfection yoke / scan coils could / will emit X-Rays but you would have to have your head on the screen for 10s of yeas if not longer to even get a medical condition.

Bad lighitng and glare cause more issues but thats down to the user !

7 12 2010

Actually CRT may cause damage to health including cancer if some of its parts are damaged or deliberately turned off. That is because of the beam of electrons travelling at a speed close to the speed of light driven by 120 watts of power will cause the changes in chromosomes. The best solution is to use screen shield – but remember to earth it otherwise it will be not that effective. If you are hit by that beam you may feel prick like someone put the long needle in your body.

15 01 2011
dangers of CRT monitors - HEXUS.community discussion forums

[…] of CRT monitors Is this true!? I never knew that they were bad for you :S anyone clear this up for […]

9 08 2011
zildjian crash

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4 11 2011
Mel Martin

this article is stupid. I had worked for 36 years at a well known monitor manufacturer in the U.S. In fact our computer designed and built the FIRST Broadcast monitor. There has never been known of anyone having this problems due to crts. I had been involved with CRTS for all of my 36years and have no symptoms. I can not believe how this information can be released by someone with no experince other than supposely using crt monitors.

29 05 2012

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1 05 2020

Good information about cathode ray tube.

“Keep it up”

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