The interviewers want to see that you are forward-thinking and have identified challenges in the field of ophthalmology. As this question is opinion-based, there is no wrong answer. However, if you have no response to what challenges you will face as an ophthalmologist, the interviewers will determine that you haven't put much thought into the future. It is also recommended to ask the interviewers what they think the most significant challenges will be. It shows you are interested in hearing what they have to say and value their experience.
