Megan shock' refers to a character named Megan in a book called Deaf Child Crossing. The book was written by Marlee Matlin and is aimed at an audience in the 8 to 12 years old range. What is meant by Megan shock is when the chacter Megan, who is deaf refuses to open her eyes as a response to stress or trauma.
When Megan is overwhelmed this may be her response to the stress of the trauma she is feeling. As a result of closing her eyes shut tight Megan doesn't have to see anyone signing to her therefore she can, in a way, ignore the world.