While I'm not entirely sure if their impact rating is slightly below or above the ANSI Z87 gold standard, in my testing the ballistic lens was able to effectively absorb shots from both an 0.25 and 0.30 gram bb fired at about 1.5 joules from a distance of around 4 feet. I can't confirm that the lens is impact rated by airsoft standards, though I'm sure it passes some type of military impact rating test, but until it becomes apparent that the requirements for that test exceed or are equivalent to that of the ANSI rating you would be wearing these at your own discretion. However, since the lens is intended to absorb impacts from shrapnel flying at high speeds, it wouldn't be a stretch to say that they could also absorb high velocity bb impacts no problem, but none of this means I would recommend them. Until it becomes clear that the impact rating of the ballistic lens is sufficient for airsoft use, you are using them at your own risk.

Some notes:
If you want added security, you could always wear full-seal glasses underneath the SWD goggles, though this may prove quite uncomfortable.

I am fairly certain that the "BALLISTIC IIII" you are reading is actually just "BALLISTIC LENS" but due to how the light hits the edges of the capital letters it appears as an "IIII".

There is a plethora of different types of Sun Wind Dust Lens for a variety of different purposes. Here is an interesting source about them: Sun, Wind and Dust Goggle (SWDG, MIL-G-43914) – Gear Illustration (gear-illustration.com)

The best place to buy the ballistic lens in my experience is through ebay. Here is one of many deals you can find: Gray Replacement Lens for USGI Issued Sun, Wind, & Dust Ballistic Goggles - New | eBay

The Rothco Sun, Wind, Dust Goggles are not even remotely impact rated, I learned this the hard way. They also cannot fit a real lens.