I suspect it's just visual and it doesn't affect battles, but I don't really know. I asked and I'll let you know when I get more details, but that's not likely to happen before Monday (Ukraine has a public holiday tomorrow).

If you want to be sure before I get back to you, you can experiment. For example, put 1k FDs (1000 Flying Dutchmen) without this lens on some inactive haven and have someone scout with 100 FDs. Then activate the lenses and have the same person scout them again. If their losses are the same, it's a bug. If they get higher losses on the second go, it's just a visual glitch.