Are you doing Taiji entirely for meditation, relaxation, and chi-kung? If so, go ahead and do it with your eyes closed. Or better yet, do it sitting down on the floor while just "thinking" of how the movement should feel. You'll make more progress at your intended purpose that way.
If, however, your purpose for learning Taiji is at least partially for martial arts (self-defense), then practicing it with closed eyes seems counter-productive. If you need your eyes closed in order to practice it, then what happens when you need to use it for self-defense? Are you going to close your eyes then? That would be ill-advised. And so, how do you think it's going to work for real when you can't even make it work when practicing it that way (with your eyes open)?
Beyond that, your eyes give you instant feedback on your balance, your position and which direction you're facing, your stance and how your body looks, etc. If you take that away during practice, it's very likely you'll be leaning too far forward, your arms will be too far away or not far away enough, your head will gradually tilt downward as if you're looking at the ground, you'll end up facing the wrong direction or you'll finish too far away from where you started, etc.
Seeing is very important during the training phase for self-correction. It's why having mirrors on the walls is so important. You have to be able to see yourself to know what needs correction. Going by feeling alone, without sight, often isn't good enough.
One other thing to realize is that the forms themselves encapsulate self-defense instruction. Where you are looking at in the form often tells you something about where your opponent is expected to be or what you're supposed to be doing. If you know how to interpret your form correctly for self-defense, this is one of the most basic pieces of information you need.
That said, you can experiment with training without your eyesight. You'll laugh sometimes at the way you look when you open your eyes to check. And maybe that can give you something you can take back into your normal Taiji practice. It's just that this probably shouldn't take up much of your practice time.
Push-hands practice is also something many people like to try without sight. It develops their sensitivity. But that's only a drill, not reality. When you go into free-sparring or realistic self-defense applications, you'll definitely need to see what's going on. Or you'll get hit.
Hope that helps.