The plural form of Glass is [[1]]

The plural form of the word "Glass" is "Glasses". 

Usage of “Glasses”

• Material Context: When referring to the substance glass, the word is considered uncountable, so it remains singular (e.g., "The window is made of glass").
• Countable Context: When referring to glass as an object, such as a drinking vessel, the plural form "glasses" is used (e.g., "The table has three glasses of water").
• Eyewear: "Glasses" also refers to spectacles, which are always plural because they consist of two lenses (e.g., "She wears glasses for reading").