Is this gecko okay?

[MadiS.]

My sister had her leopard gecko out, when I noticed that his belly was dark. I asked her to give me a better look of his underside and this is what it looked like. She takes good care of him and I'm unsure if it's impaction or just translucent skin. He's not kept on sand, she feeds him 6-7 crickets a day(all about the size of the space between his eyes), and he's eight months old.
Thanks in advance for any information you're able to give!

 

[acpart]

It's hard to tell. I've seen leopard geckos with dark bellies who are fine. He does look a bit small for 8 months, but I may not have a y agood sense of the scale. As long as he's acting normally and gaining weight it's probably fine.

Aliza