In Act II of The Importance of Being Earnest, Gwendolen says this in a conversation with Cecily:
Gwendolen: [...] And certainly once a man begins to neglect his domestic duties he becomes painfully effeminate, does he not? And I don't like that. It makes man so very attractive. Cecily, mamma, whose views on education are remarkably strict, has brought me up to be extremely short-sighted; it is part of her system [...]
What is this line's meaning and is Gwendolen insulting her mother?
To some extent, the "short-sighted" view on education is reminiscent of Mrs. Malaprop's view on the education of young women, which should be administered with moderation (R. B. Sheridan: The Rivals, 1775, Act 1, scene 2):
I would by no means wish a daughter of mine to be a progeny of learning; I don't think so much learning becomes a young woman; for instance, I would never let her meddle with Greek, or Hebrew, or algebra, or simony, or fluxions, or paradoxes, or such inflammatory branches of learning—neither would it be necessary for her to handle any of your mathematical, astronomical, diabolical instruments.—But, Sir Anthony, I would send her, at nine years old, to a boarding-school, in order to learn a little ingenuity and artifice. Then, sir, she should have a supercilious knowledge in accounts; (…).
In addition, Gwendolen's mother, the aristocratic Lady Bracknell, attaches great importance to class distinctions, even so much so that she deduces that Jack lives on "the unfashionable side" of Belgrave Square just from the house number (Act 1). It is Lady Bracknell's myopic (Victorian) view on class that he instills in her daughter that is being ridiculed by turning it into literal myopia.
I think Oscar Wilde here is making a tasty mix of literal meaning of being afflicted with short-sighted eyesight and the figurative language of a strict focus of education that limits one's knowledge to an unacceptable degree.
