I have always stated that when you are snatching or cleaning it is of the upmost importance to have a consistent line if sight. As a general rule I have my lifters keep their eyes just slightly above conversation level and remain focused on one point for the entirety of the lift. Here’s a good example of Connor hitting a PR in the snatch but his eyesight shifting throughout the lift. You’ll see from this video the receiving position that Connor finds himself in at the bottom of the OHS is far from stable. However, it was a massive PR.
Connor F. Eyesight Example