states a bug "appeared with Nvidia driver 515 and 516," with some also saying the issue is on driver 512.95, causing lines and/or flashing objects to appear on the screen, "and occurs when Advanced Lighting Model is enabled. ... Symptoms include horizontal lines on the screen, objects repeatedly flashing visible/non-visible, shadow issues on objects & avatars, and a wood-grain effect on some objects or avatars."
When it comes to graphics cards, NVIDIA is one of two brands Linden Lab recommends your computer uses. But lately, it seems the latest driver programing is causing glitches and problems.
The solution, at least until the bug is fixed, is to "roll back the driver or use the Nvidia Studio Drivers instead." Or one can turn off Advanced Lighting.
This is not the only issue. The wiki also reported recent updates on Nvidia, "including driver version 381.65," may stop Firestorm from starting up, "The crash is reported to occur on the “Detecting Hardware' step."
Another issue is with 378.49 Nvidia drivers is there may be a blue tint on 64-bit viewers when Advanced Lighting is turned off.
Team Firestorm filed about the issue with Nvidia (here).
To read more about the issue, check out the page on Firestorm's Wiki, or this article on Modem World.
Image from Inara Pey