An aircraft HUD is usually projected or focused at infinity, so the symbology should look pretty clear unless you are looking at something really close, like less than 10 meters away.

HawkeyeNFO said:

An aircraft HUD is usually projected or focused at infinity, so the symbology should look pretty clear unless you are looking at something really close, like less than 10 meters away.

I guess from our POV (pilot in cockpit) eyes are focused on aircraft, not on cockpit and HUD, that's why it is blurry.