Most headaches aren't caused by a serious illness, but some could be a sign of a life-threatening condition.

Symptom Checker

Foot pain? Headache? Sore throat? Skin rash? Use the Symptom Checker to find out what's causing your symptom.

Tests and diagnosis

Eye exam

Eye exam — Overview covers definition, what to expect and results of vision testing.

Treatments and drugs

Contact lens basics

Thinking about trying contact lenses? Here's an overview of the basic choices — plus tips to keep you seeing clearly.

LASIK eye surgery

LASIK eye surgery — Overview covers definition, risks, what to expect from vision correction surgery.

Oct. 17, 2014