I no this has been covered many times but jesus scaffolders shouldn't have to wear these I no its law on most sights but there more dangerous wearing them I got my front teeth knock out the other l year with the blurred vision they cause myself and animal the other day amended the rams with the heat and humidity as the glases had 5% vision I no you can amend the rams in rain but where do you stand on a sight were the client is not going to let you take them off when they get steamed up throw sweat and heat they scratch easy and the vision just gets worse how long is it going to be before someone gets seriously hurt throw these safety glases!!!
dico read below section4.3 of the PPE Regs, you may find that quoting the part d section may get someone to listen. I would also be asking the site manager that if they have identified that dust is a hazard getting in your eyes then why have they not specified that you wear a face mask as well (face fitting would be required if they did). It is down to your employer to provide suitable PPE and if it is blurring your vision then it is not suitable.
PS
I drove past a gang of 4 the other day all wearing sunglasses
3) Without prejudice to the generality of paragraphs (1) and (2), personal protective equipment shall not be suitable unless—
(a)it is appropriate for the risk or risks involved and the conditions at the place where exposure to the risk may occur;
(b)it takes account of ergonomic requirements and the state of health of the person or persons who may wear it;
(c)it is capable of fitting the wearer correctly, if necessary, after adjustments within the range for which it is designed;
(d)so far as is practicable, it is effective to prevent or adequately control the risk or risks involved without increasing overall risk;
(e)it complies with any enactment (whether in an Act or instrument) which implements in Great Britain any provision on design or manufacture with respect to health or safety in any relevant Community directive listed in Schedule 1 which is applicable to that item of personal protective equipment.
http://www.legislation.gov.uk/uksi/1992/2966/regulation/4/made