This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Ophthalmology
Which of the following type of cataract gives a polychromatic lustre on slit lamp examination of the eye? 
Select and explain. 
A. Complicated cataract, B. Diabetic cataract, C. Post-radiation cataract, D. Congenital cataract
A: Complicated cataract
Answer: A: Complicated cataract 
Explanation: Slit lamp examination of the lens of the eye in a case of complicated cataract shows bread crumbs like appearance and a characteristic rainbow display of colours which replaces the normal achromatic sheen (polychromatic lustre). Complicated cataract results from a disturbance of nutrition of the lens due to inflammatory or degenerative disease of other pas of the eye, such as iridocyclitis, ciliary body tumors, choroiditis, degenerative myopia, anterior segment ischemia, retinitis pigmentosa or retinal detachment. Ref: Parsons' Diseases of the Eye By Ramanjit Sihota & Radhika Tandon 21st edn page 262