BLUE TONGUE SKINKS

I have these ideas just pop into my head, and start researching. Tonight was how well blue tongue skinks can see. I have spent a lot of time researching it, and have come up with practically nothing.

From looking on my skink's behavior, she watches me like a hawk when she's out, but also startles easily if I move too fast. And of course, when I go to get her out she hisses. But I know that is just her instinct kicking in and she looks at my hand coming in as a threat.

However, her enclosure is in my bedroom and that room is darker than the night at high noon. I would expect when she looks out that she can't see a thing without the room lights on. And I've seen her move her head like she was trying to figure out what she was hearing. When I have my room lights she seems to see better, but again, she is in a bright tank looking into a darker room, as the light isn't that great in there either. How far she seems to recognize movement seems to depend on which light is on.

I'm also curious as to how the parietal eye works with what they can see in their reactions.

I know they have bad depth perception, and will just run off of something if they aren't on the floor.

I feel like I'm rambling here. I'm just curious if anyone has any idea. And if anyone watches their skinks as much as I do to notice all of what I wrote above!

Here is a previous thread I found that talks about it a bit:
viewtopic.php?t=18069

My understanding of the parietal eye is that it is designed to detect light and shadow, they are vulnerable to things bigger than them that come from above (like birds) so when the parietal eye detects sudden changes in light, ie go from light to dark (shadow) they are potentially in danger from something bigger and can hide. It might also have a role in detecting light for the purposes of light/day/sleep cycles.

Thank you!