**Question:** All are included in vision 2020, except

A. Refractive errors
B. Glaucoma
C. Retinal detachment
D. Macular degeneration

**Correct Answer:** **Option D: Macular degeneration**

**Core Concept:** Vision 2020 is a global initiative aimed at eradicating avoidable blindness by 2020. It addresses various eye disorders and their prevention, management, and rehabilitation.

**Why the Correct Answer is Right:** Macular degeneration is a degenerative disorder affecting the macula, the central part of the retina responsible for sharp, central vision. Although it can cause vision impairment, it is not an avoidable blindness disorder, making option D incorrect.

**Why Each Wrong Option is Incorrect:**

**A. Refractive errors:** These refer to conditions such as myopia, hyperopia, and astigmatism, resulting from an inaccurate curvature of the cornea or lens. They can be corrected through spectacles, contact lenses, or refractive surgeries. Options A is incorrect as refractive errors are avoidable blindness disorders and are included in Vision 2020.

**B. Glaucoma:** Glaucoma is a group of eye disorders characterized by damage to the optic nerve and corresponding visual field loss. It is often associated with elevated intraocular pressure, but can also occur with normal pressure. Although management strategies exist, glaucoma is still considered an avoidable blindness disorder, making option B incorrect.

**C. Retinal detachment:** This is a clinical condition where the retina detaches from its underlying support, leading to vision loss. It is considered an avoidable blindness disorder and should be included in Vision 2020.

**Clinical Pearl:** Vision 2020 aims to focus on avoidable blindness and provides strategies to reduce the prevalence of cataracts, trachoma, blindness due to trachoma, and other avoidable causes. Including macular degeneration among the disorders to be eliminated by 2020 makes option D the correct answer.