Why all sugars are dextrorotary?

Not all sugars are dextrorotary; however, many common sugars, such as glucose and sucrose, are indeed dextrorotary, meaning they rotate plane-polarized light to the right. This property is due to their specific molecular structures and the arrangement of their atoms. Sugars can also be levorotary (rotating light to the left) or optically inactive, depending on their chemical composition and configuration. The optical activity of a sugar is determined by its stereoisomerism, which influences how it interacts with light.