What are those blackish rings sometimes seen under peoples' eyes ...
sometimes called raccoon eyes as slang.

Hi there,

The condition popularly known as "raccoon eyes" is the result of a
skull fracture. The technical name for the condition is "periorbital
ecchymosis". Periorbital means "situated around the orbit or eye
socket". Ecchymosis means "The passage of blood from ruptured blood
vessels into subcutaneous tissue, marked by a purple discoloration of
the skin."

"In the case of bilateral periorbital ecchymosis (raccoon’s eyes),
consider basilar skull fracture, LeFort fracture, and NEO injuries."

Maxillofacial Trauma by Stephen A. Colucciello, MD, FACEP
http://www.thrombosis-consult.com/articles/Textbook/138_maxillofacial.htm

Basilar Skull Fracture
----------------------

A basilar skull fracture is often marked by hemotympanum, Battle's
sign (ecchymosis behind the ear), 'raccoon eyes' (periorbital
ecchymosis), and CSF otorrhea or rhinorrhea.
http://pedsccm.wustl.edu/All-Net/english/neurpage/trauma/head-2.htm

This is a fracture (break or crack) of the basilar bone of the skull,
which is part of the floor of the skull that holds the brain. 
Fractures in this bone can cause tears in the sack compartments that
hold the brain, resulting in a leakage of the cerebral spinal fluid
(the fluid that surrounds the brain and spinal cord). Symptoms: Eye
Bruising....
http://www.ecureme.com/emyhealth/data/Basilar_Skull_Fracture.asp

Basilar skull fracture may be suspected if Battle sign is present,
there are raccoon eyes, blood behind the tympanic membrane, and
leaking CSF from nose and ears.
http://pedclerk.bsd.uchicago.edu/headTrauma.html

A basilar skull fracture involves the cranial base. The most common
sites are the floor of the anterior cranial fossa and the temporal
bone. Evidence that a patient may have suffered a basilar skull
fracture includes "raccoon eyes" and "battle sign" (bruising posterior
to the ear, possibly including the mastoid process). Most basilar
skull fractures do not require treatment in the absence of associated
brain injury. They are a sign that a significant blow has been
delivered to the cranium.
http://www.neurosurgery.org/cns/meetings/curriculum/b1.html

A basilar skull fracture is any fracture of the skull in which the
fracture originates in or propagates to the base (lower portions) of
the skull. There are several types of basilar skull fractures
including ring fractures, in which the fracture forms a complete or
incomplete ring around the foramen magnum (the hole through which the
spinal cord passes). Ring fractures are also a diverse group of
fractures and arise from many widely differing mechanisms. These
include: impact to the chin, jaw and face; impact to the head
anteriorly, posteriorly or laterally; impact near the top of the head;
and inertial head loading, in which the spine and neck muscles are
called upon to stop the moving head.
http://www.skfriends.com/earnhardt-accident-medical-examiners-report.htm


Le Fort Fracture
----------------

Basically it is another type of skull fracture. See:
http://www.amershamhealth.com/medcyclopaedia/Volume%20VI%202/Le%20Fort%20fracture.asp


NEO Injuries
------------

NEO = nasoethmoidal-orbital. Basically an injury to the middle of the
face. See:
http://www.bcm.tmc.edu/oto/grand/1793.html


Search strategy: "raccoon eyes"


Best wishes,
robertskelton-ga

Great answer for the money.

Also called allergic shiners:
http://www.ivillagehealth.com/print/0,,187300,00.html

This was a great answer, Mr Skelton. And it deserved five stars, in my
not particularly humble opinion.

Mr Skelton's answer refers to dark rings resulting from a physical
injury.  Guessing from your question, I think you may have been
looking for "Familial periorbital hyperpigmentation" which is fairly
common in dark-skinned people, especially from India and the Middle
East.  There is extra melanin produced in the skin under the eyes
giving the "racoon" effect.  Women often can cover this up by wearing
makeup.  Some dermatologists can now lighten the skin with lasers.