Blurry GIMP interface on macOS High Sierra 10.13.6

[vagkavo]

Thanks for your answer. I am using a macbook pro, 2017 with a 13.3-inch (2560 x 1600) retina display.

check for example the attached to gimp photo in the following screenshot:
https://image.ibb.co/cA6kdU/Screen_Shot_..._33_59.png

the attached photo is crystal clear, but when I open it with GIMP, it becomes blurry