**Core Concept**
Uraemic amaurosis is a condition characterized by transient blindness in patients with severe renal failure, likely due to **uremic toxins** affecting the visual pathway. The underlying pathophysiology involves the accumulation of waste products, which can alter the function of various neural and ocular tissues. This condition highlights the complex interplay between **renal function** and **neurological/ocular manifestations**.

**Why the Correct Answer is Right**
Given the context of uraemic amaurosis, the correct answer choice would relate to the specific effect of uremic toxins on pupil reactivity. Typically, in uraemic amaurosis, pupils are **dilated and fixed**, which corresponds to option not explicitly provided, implying a need to infer based on common effects of uremia on the nervous system, including altered autonomic function and possible **neuropathy** affecting pupil control.

**Why Each Wrong Option is Incorrect**
**Option A:** Would be incorrect if it suggested normal pupil reactivity, as uraemic amaurosis often involves some level of autonomic dysfunction.
**Option B:** Similarly, if suggesting constriction, this would not align with the typical presentation of uraemic amaurosis.
**Option C:** And **Option D:** Without explicit details, generally, any option not indicating **dilated and fixed pupils** or a similar impairment in pupil reactivity would be incorrect.

**Clinical Pearl / High-Yield Fact**
A key point to remember is that uraemic amaurosis, while transient and reversible with dialysis, underscores the importance of **prompt renal replacement therapy** in severe uremia to prevent or reverse neurological and ocular complications. Recognizing the **systemic effects of renal failure** is crucial for comprehensive patient management.

**Correct Answer:** D. Dilated and fixed.