In
late 2012, Clinton was suffering from a stomach virus when she fell at her
home, struck her head and endured a concussion, according to her
representatives. Doctors later discovered a blood clot behind her right ear. Severe head trauma could
have caused double vision and Clinton’s need for Fresnel prism glasses.

Fresnel
prisms are special
glasses former Secretary of State Hillary Clinton was seen wearing last year
are used to treat double vision, which is sometimes caused by severe head
trauma.  In order to see one object, your eyes need to be pointed in the
same direction. If your eyes are misaligned, one way to optically align them is
to put a prism … on your glasses.

 Any issue which raises
intracranial pressure can damage one of the nerves which moves the eye around,
and if it damages one of the nerves, your eyes will be misaligned — maybe
temporarily, maybe more permanently.

Clinton’s
representatives, and husband, have defended her, saying she’s “100
percent.” Bill Clinton said earlier this week there’s “nothing
to” the health questions — though at the same time, he revealed her
recovery took about six months, which is much longer than the State Department
had indicated.