Possible Clues:

• Problem for reader English tutor grasps OK
• Difficulty seeing coach behind back of vehicle, certainly
• Problem for readers, I agree, in English school
• Result of prolonged screen time, maybe
• Many an office worker's problem
• Looks at Express, say, or issue of Observer
• Optical irritation or tiredness
• Problem caused by damaged retina, certainly inside
• What an obsessive spotter does and may suffer from