After I pulled out his precious plastic plant, I tried the glass lamp trick, but he knew better. Inspected it awhile, cruised thru it, went around it, over it and said no dice. He does sense light and dark. I took it out, there was no fooling him. He made up his own mind, went over to my little lava rock decoration, that's in the shade of a sword plant, and staked his claim. Its right up against the aquarium glass so I can see him all the time, but he just doesn't know it.
And he's been there ever since. Yes, I realized I made an error re: the african brown knife, he's also cool. Its the african knife, that is an aggressive predator, I think.
Mine senses light changes, he is visually impaired, but does perceive light and dark. He's not shy under the aquarium light, I believe he is well accustomed to the layout of the aquarium, and is feeling secure. Also well fed, so he has no concerns about his next meal. They kind of swim by there food, using an electrical impulse to determine the size and proximity of food, the they reverse direction and snap it up. I've seen him open his mouth to grab a too big piece of shrimp that I dropped by mistake. He can open it up a fair size. He has goten used to tank noises, as when I open and close the hood. He'll sleep through a 50% water change, laying on his back all the while, while I fiddle all around him. If I pull out his lava rock house, I have to literally shake him out of it, even as I'm taking it out of the water.
After the water is replaced he'll do a swim through just to see if here were any changes in the tank. When I added my second filter, I had no sooner closed the lifd and there he was nosing all around it for a good 15 minutes or so, then he went back to bed.
This fish is a joy.