If you require the use of glasses to do your job, you are entitled to a free eye test / money toward a pair of glasses.
If you require safety glasses as part of your PPE, for your job; these must be provided free of charge by the employer.
There are special glasses for people who look at monitors (narrow field of view etc), so you may be able to go to Specsavers and pick out a pair, but it's dependant on your company's policy regarding paying toward them.
I wear glasses, and they (the company) pay for the eyetest but as I don't require safety glasses I have to buy my own frames etc.