Matte and Glossy Screens
There are two types of laptops screens out there, the glossy screens and matte screens. Matte screens are probably the first ones used in the first laptops.
Just before the LED screen introduction, there appeared glossy screens. Usually, a glossy screen in a laptop is also a widescreen. As a backlight, it still can have a CCFL lamp as, for example, this laptop has a glossy screen, yet it still uses an old-fashioned CCFL lamp.
How do you know it is a glossy screen? The reflections will tell us about it. Even glossy screens have antireflection coating, but if you tilt it to a certain angle, you still would see a reflection, especially from a light source like in the image above.
Matte screens are still used in laptops because some people do not like reflections on laptops screens. I do not see much difference between glossy and matte screens in image quality.
The difference most likely is that, from glossy screens with LED backlight, the eyes get less strained as the glass filters out ultra violet light.
Glossy screens were introduced because they can reproduce images better. But I have an Acer Swift with a matte screen and the quality of the image is on par with my Asus laptop with a glossy screen. The Acer screen has almost no reflections. Here is my Acer Swift 1 laptop. I tried to catch a reflection on its screen from my room light. It is the same light you see in the reflection on a Dell laptop in the image above.
LCD and LED screens
LCD stands for liquid crystal display and is the first screens used in portable laptops. These screens have a backlight implemented with so-called CCFL lamps (Cold Cathode Fluorescent Lamp). If you could look inside the LCD, you will notice two slim tubes located on the top and the bottom and are connected to an inverter. The inverter does nothing more than make a high voltage so those two lamps glow. It is actually an efficient system, except the inverter is prone to failures due to the high voltage it is producing.
LED are the same LCD screens, but they do not use CCFL; they use LED (Light Emitting Diodes) instead. They are thought to produce a better picture and to be more power efficient, but it is not that simple. Because LEDs can drive substantial power, especially if there are a few of them, the lightness manipulation is implemented using impulsive power. Because of that, LEDs flicker, and we see an illusion that the screen is lit less. This is convenient but makes your eyes tired after a while.
Here is an example of an inverter.
Widescreen advantages and disadvantages
It is pleasant to watch a movie on a wide laptop screen. This pleasant experience ends when we use word processing or other software optimized for portrait view. I find it also difficult to edit pages on a website. Also, it is difficult to use Microsoft Excel because it feels that you see less area.
In the other hand, you can edit two Word documents side by side and edit two photos side by side.
What About the Eyes
I find some LED screens heavy on my eyes. However, laptops with LCD screens emit more electromagnetic field (EMF), so I am getting tired anyway.
I find some laptop brands giving me less tiredness. For example, Asus E403SA is probably easier to use, where Acer Swift 1 has stronger electromagnetic field. So, it is hard to say which laptop screen would give you less eye strain, because you get tired not only because of the screen.
I find the resolution 1366 X 768 to be OK on 14-inch screens. On bigger screens, like 15.6, it does not look good. On 15.6 screen, you need 1920 X 1080 resolution for the picture to look good. I do not use screens less than 13 inches because they are too small and make my eyes tired.
14 inches is good for word processing and perfect for business, because those laptops are very portable.
15.6-inch screens are better for media work.
Laptops with 17-inch screens are considered gaming laptops. There are even models especially dedicated for games with insane hardware specs with high screen resolutions.
There are a few laptops out there with 16.1-inch screens. There are also some weird super wide 17-inch screens.
Dell laptops are considered to have unique screens, because it is hard to get a replacement if it breaks. Other laptops can take generic screens.