Possible Clues:

• Way into Dublin port for ghost with narrow focus
• A rather narrow view of what the mole is expected to look through
• Single-mindedness that allows one to see the light, finally?
• Fixation indication
• Singer Presley stuck in a narrow outlook?
• Seeing problem in dream Napoleon had for invading England?
• Restricted sight
• Narrowness of viewpoint
• Condition where one can only see objects directly ahead
• Inability to take a wider view