Glasses on, suddenly she'd become herself -- She said she was blind without those thick lenses: her bulwark against the vide. Keeping them by her bed she'd slip them on first thing, a permanent fixture for the day.
How can I interpret this "vide"? I know it means "see". But I don't get the meaning. Does it have a connotation related to academic research or is it simply a common way of saying "see"?
Probably void or vacuum. Basically the poem is implying that her glasses are her safety net (obscure sense of bulwark) against the void ie it is simply reinforcing the previous line about her being blind without them
The word vide in this context is French, not Latin. In poetry (e.g. Sylvia Plath) the word �vide� (Fr. for �empty�) is used in place of the word void as said above. For example, "vide de signification" means empty of meaning.