Many people like to argue for political reasons that IQ tests are meaningless or fundamentally flawed. One of the typical arguments, repeated in the article, is that the questions on a test require some cultural background and a smart person can fail them if they were raised in a different culture.
Following a similar line of reasoning, we could say that the vision test your optometrist administers requires the cultural context, after all if you were raised in a culture that uses cyrillic then you might not recognize some characters, and you would fail the test even if your vision was 20/20! Therefore, all vision tests are flawed, and the very concept of vision acuity is meaningless.
At this point in the conversation, I believe I'm supposed to accuse you of being oculonormative and suggest that you are blinded by your Visual Privilege. Would this be helpful? [y/N]
Following a similar line of reasoning, we could say that the vision test your optometrist administers requires the cultural context, after all if you were raised in a culture that uses cyrillic then you might not recognize some characters, and you would fail the test even if your vision was 20/20! Therefore, all vision tests are flawed, and the very concept of vision acuity is meaningless.