It's "a pair of glasses" or simply "glasses". Since the word glasses is plural, you cannot use the article "a" with it.
It's "a pair of glasses", or simply "glasses". Since the noun glasses is plural, you cannot use the article "a".
I've just bought a new pair of glasses.
I've just bought a new glasses.
Does she wear glasses?
This object consists of two parts and only has a plural form; therefore, we cannot use "a" ("a" means a single thing). However, you can use a possessive pronoun, such as my, your, his, her, etc.
Peter, put your glasses on.
If you want to count these items, you can say "two pairs of glasses", "three pairs of glasses", etc.
How many pairs of glasses do you have?
I have three pairs of glasses.
Alternatively, you can use other determiners for plural nouns, including "these" (not "this"), "some", "any", etc.
Are there any glasses in the drawer?
But use no determiner when talking about glasses in a general sense.
Glasses are typically customized to the wearer's visual needs.
Be also aware that plural nouns, like glasses, always take a plural form of a verb; thus, we say "glasses are" (not "glasses is").
Your glasses are trendy.
Your glasses is trendy.