[Fozzie (OP)]

Their angular diameter is much smaller than the resolution of the human eye, so how come we can see them?  []

[graham.d]

The resolution does not mean we can't see small point sources, just that we cannot resolve their size (with the naked eye). Imagine an array of detectors (like the eye's light receptors); these are of finite size which limits resolution but any one will still respond to light falling on it. It is just that the eye could not resolve a space between (say) two sources next to each other.