Most employers will not hire someone for this position unless they have a high school diploma. However, it is a good starting job as most of the ophthalmic laboratory technicians learn their job right at their workplace.
This is a good job for someone who has superior manual dexterity. The person must also have the ability to perform precision work.
Most ophthalmic lab techs get training by working their job. The length of training depends, but it can take as long as 6 months to learn all you need to know to work independently.
You will start by prepping lenses and helping your superior do their tasks. You learn as you go and will advance as time passes. Your supervisor will gauge your process and determine your skill level to allow you to complete more tasks.
You could go on to complete a certificate program and learn about optical theories, dispensing and laboratory techniques, though it's not required.
These programs will broaden your skills and advance you in your career.