The reticle on Holosun sights is widely held as one of the sharpest in the industry. Even sharper than the market leaders. This is the feedback that has been given at multiple SHOT Shows by hundreds of industry members. If the shooter has un-diagnosed or under-corrected astigmatism, the dot may appear as a series of dots, starburst, a smear, or a coma shaped dot. If the shooter has used other red dot sights, the dot on those sights may not have been as sharp and thus masked the vision issue. Each sight goes through quality assurance tests at the factory and then we test the sights again when we import them into Canada. Please have someone else look at the dot to determine what they see.
A quick Google search will yield some interesting discussions. https://www.google.ca/?gws_rd=ssl#q=red+dot+sight+astigmatism