My optometrist told me I need 1 dgree prism for my prescription eyeglasses, but the optician told me to pay $100 additional for my prism! That's much to expensive for me! so does it always cost much for a prism? Where can I get cheaper one?

Prism is do not easy to be made during the process of fabrication, specially if you need it in a bifocal or progressive lenses, I suggest you www.cheapglasses123.com, which is a online shop for eyeglasses, You just need to pay $50 for your prism at this store.