You can train to be a Dispensing Optician through the Association of Dispensing Opticians (ABDO) college. It is a 3 year distance learning course with two 2 week block releases a year where you spend time at the ABDO college (Godmersham, Kent). You have to be working in an optical practice as a dispensing assistant, your practice will have to be registered and you must have a qualified Dispensing Optician as a supervisor - an ABDO member will visit your practice and talk to both you and your supervisor. As far a qualifications go you need some basic, a few C grades at GCSE (or equivalent) ideally in science/maths will be fine. Doing it this way will give you a level 7 qualification which is equivalent to a degree (but not a degree). Once qualified you will be able to use the letters FBDO after your name. Once qualified you will have to pay a membership to ABDO (currently £250 a year), professional indemnity insurance (£30 a year) and a yearly registration fee to the General Optical Council (currently £280 a year). Most major optical chains will pay this for you though. Once qualified you also have to continue your education by complete articles/attending conferences and gain 'CET' points (Continuing Education and Training) each article has either 1 or 2 points assigned to it and you have to gain 36 in each 3 year cycle.
The other way to qualify is to do the course as a degree at Anglia Ruskin University (ARU) in Cambridge. It is half an optics degree and half a business management degree. It's 3 years full time with a 1 year 'pre-registration' year where you gain the practical experience you would have had over the 3 years doing it distance learning. The course has low entry A-Levels grades (my highest grade was a D in Maths!). Once qualified you get a Batcholer of Science (BSc) degree so you would be able to proceed FBDO with BSc (hons).
Doing the course and being a DO in a busy practice is heavily maths based so confidence with maths is a good starting point for the course.
Salaries for a DO vary massively. It depends on 1. How many DO's are in the practice where you work and 2. Where you live. They can range from £16,500 in quiet independent to over £30k in a busy, high end practice in London.
Once qualified you can further your qualifications:
1. By doing the Contact Lens specialty course. 1 year by distance learning with block release time. This will allow you to fit contact lenses and preform contact lens aftercares unsupervised (and use letters FBDO CL). Once accredited you can also preform laser surgery aftercares for Ultralase. Wages for a Contact Lens Optician (CLO) average £24,000+ depending on location.
Once qualified as a CLO you can do a 1 year full time course at Bradford University to become a qualified Optometrist.
2. Doing the Low Vision course. 1 year distance learning. This will allow you to asses patients for and prescribe Low Vision Aids. Wages slightly higher than DO as work usually slotted in around your daily work.
I hope this helps
Qualified Contact Lens Optician