Just incase anyone is thinking of the same.
These are a good quality product at a reasonable price.
Volt x readers/driving glasses. They can be obtained on ebay, what can't, and come in different dioptre strengths and styles.
These are my new Volt X constructors bought to replace +1's that are years old. They are extremely light and all plastic, so much safer than glass and they fit nicely inside a helmet. Very robust.
They also do bifocals and sunnies etc. The bifocal sunnies work really well.
Hope it helps.
Upt.