Archive | July, 2012

Eyes vs LED Monitors

30 Jul

Stressed out eyes are not new thing in this age of computers and bright lights. But for some like me this is becoming a painful experience. but surprisingly when i use my macbook pro its screen which is 15 inch didnt give me that problem, neither did regular strong light source like halogen lamps, sunlight. I also thought my eye sight might be getting weaker and might need glasses, so i checked it by reading books at close proximity and at a distance, no pain. Hence concluded that it probably was not weakness of my eyes.

So I packed up my 27 inch Acer LED HD monitor and head out to the shops to check other monitors. Perhaps there was another monitor out there, which didnt have this problem, perhaps this particular piece i got had a problem.

First other Acer brands, checked the other 27 inch on display, same problem, 24, 22 and 21 inches also gave me the same problem

Second up, Samsung, a slightly better built large monitor, same problem, although i could get them to dim significantly more than the Acers, but then at low brightness conditions, all these LED monitors start showing up lag behaviors. I started seeing trails on moving objects, perhaps the refresh (which is irrelevant in flat panels) is not doing a good job, later found some tech details on it (see tech section)

Third up, Apple Thunderbolt 27 inch monitor, significantly better than samsung but for $1k, this was a monster. Apple’s resolution is an order of magnitude more than Samsung’s. Colors are more vivid, and it dims much better than the Acer and Samsung models, where dimming itself is multi step process, in Apple its just a single slider. But still my problem persisted… anywhere there is a large white space, it would give me the eye pain, but there were no trails at low light, which what i would expect from Apple.

So the conclusion is I am sensitive to the light from large display, perhaps they are pumping more photons at a different wavelengths even when dimmed to the low point. Those extra photons are the cause of my pain and headache. Also the pain/headache is a function of the area of the light, the larger the screen the more intense the pain, smaller screens had shown a lesser intensity of pain…

Its sad, i wanted a large monitor for my work, but given a choice between keeping healthy eyes and a marginal ease of work, i will chose my eyes over the marginal ease… or as the pharma ads tell, the risks of using the product is more than the benefit from it… 

Tech Stuff

LED (Light Emitting Diodes) are the standard for all modern day monitors. They make the LCD(Liquid Crystal Display) in the flat panel monitors appear more brighter, as they add more colored light to the already existing colors from the LCD. its the LCD that actually shows stuff on the screen, LED just makes them brighter.

LED’s dim/reduce their output by reducing the flicker, the more its flickers the more photons are pumped out and its appears more bright. Dimming will bring out the trails as they flicker less frequently and for  a fast eye or most normal eyes’s, a moving object on the screen will appear to have a trail following them.

LED’s are bright, very bright, but at what level do they become painful perhaps should be tester, thats why perhaps they are using it s a crowd control weapon. its called a dazzler, details here http://en.wikipedia.org/wiki/Dazzler_(weapon)

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