You might have good eyes, but a focus aid will make sharper prints more often.
I second the nomination of the Magna Sight. I modified mine using the late Barry Thornton's suggestion to attach a close up lens to the viewing lens. You can no longer focus without putting your eye right to the the eyepiece, but oh does it make for sharp focusing! With this setup you don't actually focus the grain, but instead find a sharp image line and watch it pop into focus as you adjust the enlarger.