I am trying to sort out a uniform prescription safety glasses policy for my company. This is for people going to construction sites to survey and inspect somewhere between occasionally and frequently (say, up to once a week). There's no specific hazard that we're guarding against, it's to address the increasing number of contractors requiring universal safety glasses use on site (the wisdom of that policy is a different debate I'd like to avoid - we're in the situation basically of no glasses no job, so we need the glasses). Our non-prescription safety glasses are all EN166 1F(T). We have decided F is the appropriate mechanical resistance, but being outside use (rather than indoors, eg in a factory) we need the 'extreme temperatures' rating so they are functional down to -5C, hence 1F(T). Does anyone know a supplier of single vision prescription EN 166 1F(T) glasses? I can find EN166 1F prescription glasses (eg Parmelee), but not EN166 1F(T).