A client states, "I am legally blind." Which assessment technique should the nurse use to obtain data to support the client's statement?

A. Observe the client's eye movements through the cardinal fields of vision: This test evaluates extraocular muscle function and cranial nerves III, IV, and VI. It helps detect muscle weakness or nerve damage but does not measure visual acuity or diagnose legal blindness.B. Observe the client's pupillary response to a penlight: This assesses the integrity of the optic and oculomotor nerves and reflexes, such as pupil constriction. While useful in neurological assessments, it does not determine the level of visual acuity needed to confirm legal blindness.C. Observe the client's optic disc through an ophthalmoscope: Direct visualization of the optic disc can reveal issues like glaucoma or optic atrophy. However, it does not quantify vision loss or determine functional blindness as defined by acuity measurements.D. Assess the client's ability to read a Snellen chart from a distance of 20 feet: This is the standard method for evaluating visual acuity. Legal blindness is defined in the U.S. as visual acuity of 20/200 or worse in the better eye with corrective lenses, making this test the most appropriate for supporting the client’s statement.