Thinkpads Forum

I understand that IPS screens show better color, can be seen from different angles and have a higher resolution. But are they better or worse when it comes to eyestrain? (for working on texts and using the net with a T440S/T450S)

On average, especially in laptops, IPS screens have better contrast, so they will be better for prolonged work with text with less eye strain. But that's on average. Fundamentally, contrast matters more than viewing angles for this.

However, some particular TN screens (again, especially in laptops) may have so poor viewing angles, that every little shift of your head will cause colors to change, which can by itself cause strain.

In my experience working for long periods on text with mathematics, the most important factor is how black the blacks are. Here IPS wins. Some TFT screens are OK, for example, those on the T42, but many are terrible, for example, those on the X301 and some T61 s. The website notebookcheck.net measures black levels. They should be about 0.3 cd/m^2 or less. For example, the T42/T60 IPS 15in screens are 0.30; the T42 TFT 14in is 0.64; the T61 TFT 14in is 1.1; and the X301 TFT is 1.85.

LED backlight low PWM frequency also contributes to it and blurry fonts have probably the biggest impact http://annystudio.com/misc/anti-aliased-fonts-hurt/

There are many cutting costs tricks used these days to make display look and feel crappy. All TN panels are crap and the IPS tag itself does not guarantee anything, you always have to read detailed review of the display on notebookcheck or similar web.

3 factors IMO are very important for avoiding eye strain:

1. Hich contrast, the higher the better, usually IPS have higher, but there are some pretty crap IPS available now, in which case, a TN with higher contrast may not be that bad.
2. PWM (see the above post)
3. extra color spectrum coverage, .. anything more than sRGB causes 'shiny colors' that tends to hurt over long periods of usage, there are very cheap LCDs with extra coverage of only one color, while having bad coverage for the rest of the colors, which make colors VERY yellow, or VERY red. ..etc.

hhhd1 wrote:2. PWM (see the above post)
3. extra color spectrum coverage, .. anything more than sRGB causes 'shiny colors' that tends to hurt over long periods of usage, there are very cheap LCDs with extra coverage of only one color, while having bad coverage for the rest of the colors, which make colors VERY yellow, or VERY red. ..etc.

I am quoting myself to update my view on this point.
extra saturation are more hurtful when a screen has PWM, so ..
if your screen has PWM, reducing color saturation make things less straining.

extra saturation + PWM is pretty horrible and unusable in some cases.

I still could be wrong though, no enough testing to validate my point.