The more common cause of blurred eyes in children is amblyopia due to refractive error and in teenagers is myopia. If you experience symptoms, you can go to an ophthalmologist for a refractive eye examination to clarify the cause. There are also less common causes, such as intraocular tumours, that can affect vision and cause blurred eyes. However, there are usually other symptoms, such as pain and abnormal appearance, which need to be judged based on the patient’s specific clinical presentation and relevant tests.