As a child, I got to see a perfect full solar eclipse at mid day on a clear sky. I took the glasses off for a few seconds when the sun was perfectly behind the moon and it was amazing. It felt very comfortable to look at, no afterimage at all; except in my memory... The memory is still there after 15+ years.
When the sun is fully eclipsed, you can look at it without damage.
When it's not, you can't. But it may not appear "as bright" when it's partially eclipsed, it may be "easier" to stare at it, without reflexes kicking in to stop it, and do permanent damage to your eyes.
