**Blindness Definition**

### **Core Concept**
Blindness is a severe visual impairment that affects a person's ability to perform daily activities, and it is defined as a visual acuity of less than 3/60 in the better eye with the best possible correction. This definition is crucial in clinical practice, as it helps healthcare providers identify individuals who require specialized care and support.

### **Why the Correct Answer is Right**
The correct answer is based on the World Health Organization's (WHO) definition of blindness, which considers a visual acuity of less than 3/60 in the better eye with the best possible correction as blindness. This definition takes into account the individual's ability to perform daily activities and requires a comprehensive assessment of their visual function. The WHO's definition is widely accepted and used globally to classify visual impairment.

### **Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not provide a clear definition of blindness. Visual acuity is an important factor in assessing visual impairment, but it is only one aspect of the WHO's definition.
**Option B:** This option is incorrect because it refers to a visual acuity of less than 6/60, which is actually the definition of low vision, not blindness.
**Option C:** This option is incorrect because it does not provide a specific definition of blindness and is too vague.

### **Clinical Pearl / High-Yield Fact**
It's essential to remember that the WHO's definition of blindness takes into account the individual's ability to perform daily activities, not just their visual acuity. This highlights the importance of a comprehensive assessment of visual function in clinical practice.

### **Correct Answer: D. Visual acuity of less than 3/60 in the better eye with the best possible correction.**