Sometimes poems just come to you, for no discernible reason, and then only need minor tweaking at most. This one's always said pretty much what it was supposed to say, and has never needed more than a little smoothing out to say it. No doubt you could have a better poem on the general theme, but, beyond possible slight tweaking, further revision of this poem would end up essentially turning it into a different kind of poem. Whether a poem has reached its final state is not purely a question of quality; sometimes you've just done as much as you yourself can do with those kinds of materials. Perhaps it's a grand masterpiece, and perhaps it's just a minor still life, but with poems as with everything else in life, there's always a point at which you've basically done what you were doing with it.
Shaded Isles
Alas, no more the morning light
will catch the eye and spark to sight
the verdant earth, the azure blue,
and every other rainbow hue
that vests the world to make it bright;
alas, no more the morning light
will understanding's power fire
with vision and with heart's desire,
with waking thought and morning grace
as sunlight gladdens loving face;
instead the darkness, old and deep,
shall turn your eye and heart to sleep
and dreams no more shall haunt your brain,
nor tragic hopes, nor sorrow's pain,
but somewhere, lost in shaded isles,
your thought will stop to rest a while.