A man has his eye checked during a medical campaign in Sanaa, Yemen, Sept. 16, 2019. A five-day medical campaign was launched on Sunday to provide free examination and surgery for people with eye illnesses. (Photo: Mohammed Mohammed/Xinhua)

A man with eye illness waits to receive free treatment during a medical campaign in Sanaa, Yemen, Sept. 16, 2019. A five-day medical campaign was launched on Sunday to provide free examination and surgery for people with eye illnesses. (Photo: Mohammed Mohammed/Xinhua)

A man has his eye checked during a medical campaign in Sanaa, Yemen, Sept. 16, 2019. A five-day medical campaign was launched on Sunday to provide free examination and surgery for people with eye illnesses. (Photo: Mohammed Mohammed/Xinhua)

A man with eye illness waits to receive free treatment during a medical campaign in Sanaa, Yemen, Sept. 16, 2019. A five-day medical campaign was launched on Sunday to provide free examination and surgery for people with eye illnesses. (Photo: Mohammed Mohammed/Xinhua)

People with eye illness wait to receive free treatment during a medical campaign in Sanaa, Yemen, Sept. 16, 2019. A five-day medical campaign was launched on Sunday to provide free examination and surgery for people with eye illnesses. (Photo: Mohammed Mohammed/Xinhua)

A man has his eye checked during a medical campaign in Sanaa, Yemen, Sept. 16, 2019. A five-day medical campaign was launched on Sunday to provide free examination and surgery for people with eye illnesses. (Photo: Mohammed Mohammed/Xinhua)

A man with eye illness receives treatment during a medical campaign in Sanaa, Yemen, Sept. 16, 2019. A five-day medical campaign was launched on Sunday to provide free examination and surgery for people with eye illnesses. (Photo: Mohammed Mohammed/Xinhua)