Why are these zoos looking like this

[Jyetman]

The zoos in question are the ones back left. During the day their partially closed when lights go off and moonlights come on they'll open up more normally any ideas? I've had them for several years and they started doing this several months back.

 

[ReeferBill]

I have zoas in my tank spreading like mad . I got a frag of those radioactive eyes and they just melted in a week?

 

[jdstank]

What kind of lighting are you using, how far from the surface is it and how far down are these zoas?

 

[Jyetman]

I've had these radio active for two years and are the hardiest had others close tight while these guys survive. The zoas in the picture are mid level and directly under acrylic center brace. Been running less seagel since Phos & nitrates were reading zero thinking they need more nutrients. The lights are 160 Watt Maxspect Razor 10k LED A:82/B:100 and 11" above water line.

 

[A. Grandis]

If you're talking about those 2 polyps on the left, looks like there is something irritating them.
Take a look closely and you'll find out! Could be a tiny vermitid snail or something similar...
If you can't find anything it's probably something too small, like bacteria. Normally they open after a while.
Not a big deal.

Grandis.