It’s good to spend time looking at wide, open spaces. Things like the ocean, mountain ranges, or open valleys let your eyes focus on far distances, which helps relax the tiny muscles that control your vision.
Most of us are constantly surrounded by close-up environments - walls, screens, offices, neighborhoods - so our eyes rarely get the chance to rest. When you look far into the distance, your eyes shift out of that constant near-focus tension and actually start to heal and reset.
I remember reading "The Art of Seeing" by Aldous Huxley, where he talks about this exact idea. Huxley had terrible eyesight when he was young but was able to recover much of it through techniques developed by Dr. Bates - simple exercises that focus on relaxation and awareness.
It really comes down to being mindful about how you use your eyes. Relaxation, light, and distance all play a part in keeping clear vision and a clear mind.