TEL AVIV – Former Israeli President Shimon Peres’ condition remains serious but saw “real improvement” Thursday morning, his physician and son-in-law said.

Peres’ doctor, Rafi Walden, added that it was likely his condition would remain this way for the coming days.

On Wednesday, Prime Minister Benjamin Netanyahu visited the elderly statesman in the hospital, and told reporters following the visit that he was optimistic.

“I think I speak for the whole nation of Israel, and those outside Israel, who feel a sense of relief tonight,” Netanyahu said.

“He’s better tonight than he was a night ago, and I hope he will be better the next night.”

A day earlier, Peres suffered a massive stroke and initial tests showed he suffered from a “chemical imbalance.” A CT scan revealed internal bleeding in the brain.

Two days later, the Nobel Peace Prize laureate is still on a respirator and sedated but has responded to stimuli. On Wednesday, his son-in-law maintained that Peres is “responsive and understands what is being said to him.”

Walden’s wife and Peres’ daughter, Tzivia, said her father “opened his eyes for several minutes.”

His son Chemi also expressed optimism on Wednesday.

“My father is a special man. I remain optimistic although these are not simple hours,” he said.

“It seems that we will soon be required to make decisions but not at the moment. Everything depends, of course, on how things develop.”

“I know that my father did not care about anything as much as he cares about people, as much as he cares about Israel, the Jewish people and the people in Israel. And I will take this opportunity on his behalf to send all of you his love.”

Netanyahu praised the staff for their “dedicated care” and said the country “will continue to hope and pray and trust you.”

He also described the 93-year-old as “an outstanding human being.”

When news broke of the stroke on Tuesday, Netanyahu tweeted: “Shimon, we love you and the whole country is wishing you a speedy recovery.”

Peres is known as the last of Israel’s founding fathers. He was recruited into political life by Israel’s first prime minister, David Ben-Gurion. Over his seven-decade career, Peres held nearly every major position in the Israeli government, including serving as prime minister twice, as well as extended tenures as defense, foreign and finance minister.

He won the Nobel Peace Prize in 1994 for his role in the Oslo Peace Process and most recently served as the country’s president from 2007-2014.