Hillary Rodham Clinton sported a pair of thick-rimmed black glasses during her hearings for the attacks on the Benghazi consulate due to a symptom of her concussion.

Clinton was supposed to appear before the congressional committees over a month ago, but was unable to attend due to a dehydration-induced fall that resulted in a concussion. Then, further complicating matters, the Secretary of State was revealed to have a blood clot. Although Clinton had recovered enough to take her seat at the hearings and bear witness to what occurred on September 11, 2012, she was still dealing with after-effects of the concussion.

Following the concussion, Clinton's eyesight was impaired, as often happens when one sustains such an injury to the head. In order to correct the double-vision, Clinton has been wearing glasses. "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."

While the double-vision should heal itself over time, it has yet to do so, necessitating Clinton to wear them for the hearings. "It is possible that blurred or double-vision can last up to weeks and even months," Dr. James Liu, director of the Center for Skull Base and Pituitary Surgery at the Neurological Institute of New Jersey told ABC News. Upon closer inspection, one can spot vertical lines on the left lens of Clinton’s glasses. The additional corrective feature is called a fresnel prism that can easily be attached to existing lenses. The lines alter the way in which light enters the eye, and ultimately correct double-vision.

Clinton is set to step down from her post as Secretary of State in the next couple weeks. The former First Lady and New York senator has said that she's ready for some time off from national politics so that she can spend time reading books and traveling without the diplomatic agenda. Although many expect her to run in the 2016 presidential campaign, Clinton has yet to confirm any such plans.

Watch Clinton as she gets choked up testifying before the Senate committee:

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