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
A sign of Aphakia ? 
Select and explain. 
A. Shallow anterior chamber, B. White pupillary reflex, C. Absent 1st & 2nd Purkinje images, D. Iridodonesis
D: Iridodonesis
Answer: D: Iridodonesis 
Explanation: Ans. is 'd' i.e., Iridodonesis Aphakia Aphakia refers to absence of crystalline lens from the eye. Most common cause of aphakia is surgical removal of cataractous lens. Other causes are congenital absence of lens, traumatic absorption of lens matter and posterior dislocation of lens. The typical signs of aphakia are deep anterior chamber, iridodonesis (tremulousness of iris) and a dark pupillary reflex. Only 1st and 2nd Purkinje images are present, 3rd and 4th are absent. As the lens is not there, eye become highly hypermetropic. Therefore, principle of treatment is to correct the error by convex lenses of appropriate power. Intraocular lens implantation in posterior chamber is the treatment of choice. Other treatment modalities are spectacles and contact lenses.