MacOS – 2013 Macbook Air not showing 1440p Option on External Display

With the Display pane of System Preferences visible, hold down the Option key and the "Gather Windows" button in the lower right should turn into a "Detect Displays" button. Click on that button and your computer should take care of the rest.

The MacBook Pro (Retina, 13-inch, Late 2013) has an Intel Iris 5100 GPU and is capable of supporting an HDMI-compatible device, including 4K, while using one Thunderbolt display or it can support two Thunderbolt displays.

In terms of external resolution, this model supports up to 3840 x 2160 pixels at 30Hz or 4096 x 2160 pixels at 24Hz (using HDMI) or up to 3840 x 2160 pixels at 30Hz (using Thunderbolt).

According to the specs of the Acer R241Y, this has a maximum resolution of 1920 x 1080 at 60Hz. And, according to the user manual, this resolution is achieved using VESA mode.

Possible solutions

1. On your MacBook Pro:

   • REFRESH RATE - As a first step, I would check the Refresh Rate set in your MBP. You can find this under the Display tab within System Preferences > Displays. If you change it, you may need to wait a couple of minutes to ensure the change has taken effect properly.
   • RESOLUTION - I would also double-check you're not using the Scaled option for your resolution. Instead, make sure you have the Best for display option selected - also found in System Preferences > Displays.
   • RESET NVRAM - It may be worth resetting your NVRAM. If you're unsure how to do this, refer to my answer here. Make sure you look under the PRAM/NVRAM heading.

NOTE: If, at any point, the display switches off after configuring options in your Displays System Preference, just press the Esc key to undo the last change.

2. On your Acer R241Y display:

If you're still having issues after checking/trying each of the above, try the following:

• Mode type - If your display is already in Auto mode, manually try each of the others (e.g. Standard mode, Graphic mode, etc) one by one. If it's already on a specific mode, then try it in Auto mode instead.
• Focus - You can also manually configure the display's focus. You should be able to do this by going to the Picture Menu.
• Reset your display - There should also be a Reset option on your display's menu. It may be worth trying this if all else fails.

[EDIT]

Since your issue is around how fonts look, there is also a setting in your System Preferences > General. Maybe try ticking/unticking the Use LCD font smoothing when available option to see what difference that makes.