Given it can be indicated for glaucoma, this is not a big surprise.<p>Ability to focus is impacted by a great many things, including alcohol.<p>The more interesting findings may include changed pattern recognition. Anecdotally, when I was experimenting in my twenties, I looked at a cardboard box and found the company logo very lightly embossed in the cardboard. It's not visible normally.<p>I had traced it with a marker, and found myself able to see it when sober again, and still can to this day see those patterns. It is like my mind learned to see something that it had previously learned to ignore, or that was in the noise level.