Possible Clues:

• Complaint as regards public transport
• Cause of blurry vision, perhaps
• Surveys school for tiredness of pupils
• Irritation that's right inside diseased retina?
• Stress on mince pies (in the East End)?
• Eat resiny mix to cause optical pressure
• Avid reader's complaint
• English certainly try to get fit - this could require attention from ophthalmologist
• Optic stress
• Overlooking trouble