ABC News: The thick glasses Hillary Clinton has been wearing in public since returning from a concussion and blood clot last month are the result of lingering effects of her health problems, a Clinton aide confirms.
"She'll be wearing these glasses instead of her contacts for a period of time because of lingering issues stemming from her concussion," said spokesman Philippe Reines. "With them on she sees just fine."
During more than five hours of testimony before Congress Clinton could be seen wearing glasses that appeared to have a thick left lens with lines across it.
Reines did not specify what type of lens the secretary was wearing, but medical experts say a fresnel prism is common in cases like these. Fresnel prisms usually come in the form of a piece of thin, transparent plastic that can be adhered to existing lenses. The special grooves in these prisms change the way light enters the eye, making them useful in treating double vision.