Like many of you, we use a well know high street spectacle seller to provide our prescription safety glasses using vouchers. I'd not given it much thought, but its been brought to my attention that the lens strength is EN166 S and maybe F is more appropriate. We just use these for light eye protection. Any thoughts? Anyone else considered this?

They (assuming we're talking about the same organisation) provide 'S' by default, but they are capable of providing 'F' (though at much greater cost). S is not appropriate for our use, so I haven't thought about in more detail than that. S isn't even classed as impact in the standard - it's 'reinforced solidity' and is a larger projectile (22mm diameter ball) at very much lower speed – a 1.3m drop giving an impact speed of 5.1 m/s, rather than the 45 m/s impact for F. For us, this clearly isn't good enough, but your risk assessment might conclude that it is adequate.

No, sorry - having established they didn't do what we wanted I didn't investigate further.