This article explains if antiglare coating affect the image on a monitor

Antiglare coating scatters ambient light to reduce glare, and by the same process the emitted light of the image is also scattered, which softens the image somewhat.  Antiglare provides a high quality image while at the same time reducing glare and reflections. 

The crispest, sharpest image is obtained by using a “clear” screen (one that has no coatings, or only antifriction coating). The price paid for the crispest image is a tendency for strong reflections, particularly from external light sources.  Also, the darker the image background, the greater the likelihood of reflections.  When using a clear monitor for public applications, try to avoid tilting the monitor upward toward light sources.