Display Screens and Eye Damage

[AlanHo]

I have been experiencing eye strain for several months - and occasional bouts of slight double vision when reading text.

 

A couple of weeks ago I was reading an article which expressed concerns about using a computer (me), a tablet or phone for a couple of hours or more a day (me); especially at night (me) when your pupils are dilated because of the low levels of ambient light around you. It claimed that you are in danger of damaging your retina due to excessive exposure to ultra violet light from the screen. This is especially a problem for diabetics (me).  

I exacerbate this problem by reading my kindle paper white in bed with no lights on.

 

The article suggested that if your device has the facility - switch on the night light settings for the display. This reduces ultra violet emissions by moving the display colour temperature away from the blue spectrum and towards the red.

I did this to my computers and phone (and turned down the brightness of my kindle) 2 weeks ago and have stopped seeing blurred text or suffering from eye strain.

 

I pass this on for what it's worth.

[-pops-]

Good advice, Alan.

When I had my cataracts removed the surgeon strongly recommended that I have UV absorbing glasses for use with computers and the like. I did this and I also have a pair with UV plain glass for watching TV. I've found that the eye strain has all but disappeared from what it used to be before the surgery - which I put down to merely being able to see properly again but, from what you have said, it could very well be caused by UV light from screens.

 

At least now we don't have to worry about low power Xrays as we did with CRT displays.

[andsome]

I will look into this for TV watching.

[andsome]

Just telephoned the optician, and my specs bought in March were supplied with UV protection.

[-pops-]

I think most glasses have UV filters but, as I no longer need glasses for distance vision (after the operation) I don't have that protection. Also, cheap reading glasses are unlikely to have a UV coating so that is something to watch out for.

[andsome]

1 minute ago, -pops- said:

I think most glasses have UV filters but, as I no longer need glasses for distance vision (after the operation) I don't have that protection. Also, cheap reading glasses are unlikely to have a UV coating so that is something to watch out for.

Mine are prescription specs

[AlanHo]

I have a Japanese Hoya and German Zeiss spectacles; both have photochromatic varifocal lenses with UV coatings.

 

However - the fact that my eye strain has disappeared since I set my screens to a night light setting suggests that the UV coating on spectacles may be fine for sunlight but not as effective with the high UV levels emitted by LED and Oled screens. 

 

The problem seems to be related to the fact that your pupils dilate when presented with high light levels across the full visible spectrum - like natural light - whereas with computer and phone screens a high proportion of the light is biased towards the high frequencies beyond blue. Hence at night, with low levels of ambient light, your pupils are dilated and let in more of the UV light. 

 

Hence the argument that it is more effective to cut out the UV frequencies and thus lower the average frequency of the light emitted from the screen to inhibit dilation of your pupils.

 

In Win 10 the night setting does not effect the cursor - it remains bright white. This screen shot does not really illustrate how bright the cursor is - but imagine the whole of your screen this bright to get some idea of the difference.

 

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