It depends alot on the ambient lighting levels.
In a well lit city, such as downtown, I don't find 90 lumens blinding, just annoying.
That said, it also depends on the reflector, and what they do with that 90 lumens. If it is all focused into the face, it has a stronger effect. The drawback is that it is easier for them to move out of the beam. But, all you need is an initial direct hit in the eyeballs.
Where out in the countryside, 60 lumens on a moonless night is quite dazzling, and the unfortunate soul, walks around dazzled for some time.