To measure visual acuity, a standardized visual acuity chart is used. The patient’s visual acuity is defined as the ability to distinguish the number corresponding to the smallest line of the reticle.
The visual acuity test is a subjective test and is performed with the help of a standardized visual acuity chart. The patient sits 5 meters in front of the chart in an adequately illuminated environment, looks at the chart with the right eye alone, observes the direction of the openings of the reticle line by line, and the number corresponding to the smallest line of the reticle that can be distinguished is the result of the patient’s visual acuity test. Repeat the test with the left eye.
Under normal circumstances, the naked eye visual acuity should be able to reach 1.0, if it is less than 1.0, it may be caused by physiological factors, such as the child has a reserve of hyperopia, or it may be caused by pathological factors, such as refractive error or ocular diseases leading to vision loss, and it should be promptly consulted by the ophthalmology department of the regular hospital.