Possible Clues:

• One in the eye with 29 across for the pig, by the sound of it
• Swelling troubling your eyes primarily
• Filthy thing close to eye
• There's one in the eye that sounds like a dirty one!
• Optical intrusion?
• Tamworth residence said to be an eyesore?
• Pen note making a personal complaint
• Sore point, driving pupil out of class
• Eyesore you once found on street
• Crusty, edible cases a problem for mince pie