To be declared legally blind, an individual must have visual acuity of: a. 20/200 or less b. 20/50 or more c. 20/20 d. 20/200 or more

Problem Breakdown

1. Identify the correct visual acuity that qualifies as legally blind.
2. Understand the terminology and measurement used in visual acuity.

Relevant Concepts

• Visual acuity is a measure of the clarity or sharpness of vision, often expressed in a fraction.
• A standard visual acuity measurement is represented as "20/x", where "20" refers to the distance at which a person with normal vision can see, and "x" refers to the distance at which the tested person can see.

Analysis and Detail

1. Understanding the Options:

   • a. 20/200 or less: This means that at 20 feet, a person sees what a person with normal vision sees at 200 feet. This is generally used as the threshold for legal blindness.
   • b. 20/50 or more: This indicates better vision than legally blind.
   • c. 20/20: This represents normal vision.
   • d. 20/200 or more: This would imply vision better than the legally blind threshold.

2. Determining Legal Blindness:

   • The commonly accepted medical definition of legal blindness is a visual acuity of 20/200 or worse in the better eye, with corrective lenses.

Verify and Summarize

• Given the definitions and clarity of visual acuity measurements, only option (a) is in line with the established medical criteria for being declared legally blind.

Final Answer

The correct answer is a. 20/200 or less.