The first two wave types, P and S , are called body waves because they travel or propagate through the body of Earth. The latter two are called surface waves they the travel along Earth's surface and their amplitude decreases with depth into Earth.
The causes are many and can have bacterial infection, seborrheic dermatitis of the face or even a scalp, rosacea, allergies, and in very rare cases, the lice. If the itchy eyelids is brought about by seborrheic dermatitis then you may develop dry, flakey patches of skin on the eyelid.
Swelling of the eyelids is a symptom of an underlying cause, such as allergy or infection. Swollen eyes usually are accompanied by one or more of the following: A swollen eyelid may be a symptom of allergies or a sign of a serious eye infection. Eye irritation, such as an itchy or scratchy sensation.