Translation:I want to buy new glasses.
Yes. Think of it as a scale:
想 (xiǎng) 'thinking about/want to" → 要 (yào) 'want/need to' → 得 (děi) 'have to'
Of course it should be, but it's not. Laaaawd, this is so frustrating! Reported!
We say a pair of glasses like a pair of trousers or a pair of shoes. There are two of them in one frame.