How nearsighted is 0.9?

Visual acuity refers to the sharpness of the eye’s vision, and myopia is two different concepts, because there are many factors that affect visual acuity, and you can’t usually determine the amount of myopia a patient has through visual acuity.
Myopia can lead to vision loss, generally the higher the degree of myopia, the more pronounced the vision loss of the patient. However, there is no one-to-one quantitative relationship between myopia and visual acuity, and the patient’s myopia cannot be inferred from the patient’s visual acuity.
In addition, there are many factors affecting the patient’s naked eye vision. Besides refractive factors such as myopia, hyperopia, astigmatism, etc., cataracts, fundus injuries, corneal diseases, etc. can also lead to a decrease in the patient’s naked eye vision. Therefore, it is not possible to determine the degree of myopia simply by visual acuity, and patients can clarify the degree of myopia through optometry.
It is recommended that patients with significant vision loss should consult a doctor in time to assess their condition and follow the doctor’s instructions for treatment.