Shock to the system, and what the start of each answer to a starred clue can be

• E, it seems, is a source of wonder
• Startling disclosure
• Enlightening event
• Shot at dawn?
• Wake-up call, perhaps
• Source of sudden understanding
• Morning coffee, for one
• Shocking disclosure

Wikipedia Word definitions in Wikipedia
Eyeopener are a British dance group that emerged in late 2004. Their first hit , which reached #16 on the UK Singles Chart , was a remix of Eric Carmen 's " Hungry Eyes ". One of their later songs , "Sexy Eyes", was then in the track list of Clubland 7 .