**Question:** Cataract is caused by all except –

A. Age-related cataract
B. Trauma-induced cataract
C. Inherited cataract
D. Medication-induced cataract

**Core Concept:** Cataracts are a common opacity or clouding of the eye's lens, leading to a decrease in vision. They can be classified into different types based on their causes.

**Why the Correct Answer is Right:**

Option A (Age-related cataract) is related to the normal aging process and is not considered an exception. It is the most common type of cataract.

Option B (Trauma-induced cataract) refers to cataracts caused by physical injury to the lens, which is not part of the multiple-choice options provided.

Option C (Inherited cataract) represents a group of cataracts caused by genetic mutations, which are also not specifically excluded in the question.

Option D (Medication-induced cataract) refers to cataracts caused by certain medications, such as corticosteroids. While medication-induced cataracts are a type of cataract, they are not mentioned as exceptions in the question.

**Why Each Wrong Option is Incorrect:**

Option A (Age-related cataract): Age-related cataracts are a normal part of the aging process and should not be considered an exception. They are the most common type of cataract.

Option B (Trauma-induced cataract): Trauma-induced cataracts occur due to physical injury to the lens, which is not a type of cataract mentioned in the options provided.

Option C (Inherited cataract): Inherited cataracts are caused by genetic mutations and are not specifically mentioned as exceptions in the question. They are a separate category of cataracts.

Option D (Medication-induced cataract): Medication-induced cataracts are caused by certain medications, such as corticosteroids, and are not mentioned as exceptions in the question.

**Clinical Pearl:**

Nuclear cataract, a type of cataract, is often associated with the aging process and is not mentioned as an exception in the provided options. It is essential for medical students to understand the various types of cataracts and their causes to provide accurate diagnoses and treatments to patients.

In this question, the correct answer is not explicitly mentioned as an exception, but it is implied that the question is asking for types of cataracts that are not caused by the listed factors (ageing, trauma, genetic mutations, and medications). The correct answer should be nuclear cataract, which is a type of cataract that develops within the nucleus of the lens and is a common manifestation of the aging process.

**Correct Answer:** In this case, the correct answer is **nuclear cataract**, which is a type of cataract that develops within the nucleus of the lens due to the aging process.

Understanding the different types of cataracts, their causes, and their effects on vision is crucial for medical professionals to accurately diagnose and treat patients with