I think this is an oversimplification. The cornea differs quite a bit from skin histologically. Even if light does stop at the first layer of the cornea - the question is how? The problem typically found with UV wavelengths is opacification of the cornea/lens (cataracts). I have no idea if this is the case for the specific wavelength in the paper - but it’s definitely worth more discussion

All their citations have to do with skin penetration. The one that even mentioned the cornea only did so in reference the amount of UVC reaching the lens. These authors make claims which, while possibly true, are not found in their cited literature. For example, they say far UVC cannot penetrate the tear layer. Their citation doesn't say that. The citation says it's unlikely to damage human cells between 10 and 25 micrometers in diameter. The tear layer averages three micrometers in thickness, and it does not contain the absorptive proteins responsible for the shallow flesh penetration depth. This is shoddy science.

Chronic exposure to 240nm light causes keratopathies. 222nm is not 240nm of course but I would demand a better study before I agreed to 40+ hours a week of exposure to far-UVC.