
You can ring the college at Potters Bar and make an appointment for their eye testing, with out going through the vet. I have the contact details if you PM me I can give them to you.
The other way to find out is to look in the papers for a local eye testing session where you will get the test done a bit cheaper.
By the way,the eye testing in Haddenham Bucks, is now to be held on the 3rd July not the end of June.