The color of Cassia seed ranges is green-brown, with a smooth and shiny surface. Since ancient times, Chinese people have used Cassia seed as a daily tea to help promote clear vision.\n\nTake 15 to 20g of Cassia seed and add water. Boil and simmer for 15 minutes. Let it cool and drink the tea. Slightly roasted Cassia seed can be boiled for 15 minutes and consumed daily, similar to barley tea.