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
[{'content': 'Soft contact lenses are made from which one of the following materials? \nSelect and explain. \nA. Poly ethyl methaacrylate, B. Hydroxy ethyl methacrylate, C. Silicon, D. Glass', 'role': 'user'}, {'content': 'Answer: B \nExplanation: Hydroxy ethyl methaacrylate is a soft, flexible, water-absorbing, plastic used to make soft contact lenses. It is a polymer of 2-hydroxyethyl methacrylate (HEMA), a clear liquid component. Hard contact lenses are made from polymethyl methacrylate (PMMA) and Silicon.', 'role': 'assistant'}]