The new 27-inch 2560×1440 LED display bundled with the new iMacs is one of the most outstanding monitors (and values) in computing today.

With the same resolution and better specs than the Apple 30-inch Cinema display, the lowest end iMac with this panel is $100 less – and comes with a pretty nice computer!

But I don’t expect it will be too long before we start hearing some complaints of user eyestrain and headaches due to the density of the pixels in a space significantly smaller than the Apple’s 30-inch.

A few years back it wasn’t unusual that you would be able to purchase a 15″ laptop with a native screen resolution of 1600×1200 (UXGA).

Sounds great on paper – higher-res = better image and video viewing and more screen real estate, right?

Well, yes, but the tradeoff is that interface elements start to get really tiny and difficult to read- especially text, and especially for users over age 40.

I bought an 15″ Acer UXGA notebook several years back. It looked great in the store, but after 4 hours of it on my desk I realized my eyes would never adjust and promptly returned it. I think alot of other people did too, which is why you don’t see this kind of resolution jammed into notebooks as much.

Curiously, desktop LCD monitors up to 19″ have never really gone above 1280×1024 resolution, so its kind of odd to wonder why notebook makers once liberally sold 15″ panels with such a tiny dot pitch as mainstream.

There are a few holdouts – the 17″ MacBook uses a 1920×1200 resolution -the same dot pitch as a 15″ UXGA notebook. Most people are used to seeing this resolution on a 24″ display, so it’s a pretty tight squeeze.

Some netbooks also try to squeeze a lot of pixels on tiny screens never seen before on consumer notebooks. The Sony Vaio P probably holds the crown for tiniest dot pitch of any consumer LCD – it has an 8-inch screen with 1600×768 resolution!.

Yes, you can bump font sizes when text size gets too small, but how this affects the appearance and usability of your system or individual apps can vary widely. In general, your OS was designed with a rough idea of font size in mind and you will be better off to not use a dot pitch which works against this assumption.

Contributing to the iMac’s display problem is that it sports a glossy screen which can make things worse if your workspace causes reflections. Apple gets a lot of heat from users for its lack of matte display options.

Because office workers prefer to sit facing their cube or office entry (so prying eyes cannot look over their shoulder), its actually more likely that a workspace with a window will be arranged with the monitor facing it. With a matte screen, this is tolerable – with a glossy, it sucks.

Gizmodo’s Brian Lam noted issues with his using the display in his 27-inch iMac Review:

The default brightness is a bit much, but of course you can turn it down. And the contrast is welcome; even my new 13-inch MacBook Pro looks yellowed and washed out next to it. But at this pixel density, which is sharper than my notebook, it’s almost too sharp, requiring me to sit closer than I would ordinarily do with a 27 inch display. I like the feeling of crispness — 16% crisper than the last generation. But my eyes feel like the pictures are being delivered by a land shark holding a laser pointer straight into my corneas, and I can feel the strain within minutes. I would have to jack up as many font sizes as possible or sit as close as I do to my MacBook to make it work for long long periods of time. Maybe I’m just a wimp of a geek, but I’ve never been sensitive to these sorts of things on any sort of machinery before.

I’ve used the 27-inch display at the Apple Store and didn’t have any problems with it, but that was the case with the UXGA notebook I purchased also – you really need to sit down and do a day’s work with it to figure out whether it will be an issue for you.

It also doesn’t help to get other people’s opinion – I’ve found that when it comes to dot-pitch tolerance, YMMV.