MEMPHIS, Tenn. (AP) — The latest research on the ability to bounce back after bad things happen shows that being grateful, hopeful and realistically optimistic are among key traits in resilient people.

Eighty-year-old Memphis attorney John Dunlap and his wife, Marcia, could be a case study.

Twenty-six months ago, their schizophrenic son Andrew attacked them in their Southwind home. The injuries blinded Dunlap. He's in total darkness.

At home most evenings, John unbuttons and removes his white dress shirt and — counting his steps and remembering which way to turn — carefully walks with a tall white cane from the living room to the dining table.

Marcia goes to the laundry room where plastic containers of water with wriggly leeches are stored. She sets the containers on the dining table along with a crate of the cotton balls and adhesives to make bandages.

After draping and pinning a large, peach-colored towel around John's neck, Marcia reaches into the water for the skinniest leeches. Those are the hungriest and most likely to latch onto John's face.

One at a time, she gently presses four leeches to the skin around John's left eye and three around the right. She waits patiently wait for each to bite and stay connected to John's skin.

"You can feel a bite," he says. "A little, stinging bite... And then after a while you don't feel anything."

One of the leeches refuses to bite. So Marcia pricks John's finger with a diabetes-testing lancet and guides that finger to spread the blood near his eye to entice the parasitic worm to latch on. The trick works.

The leeches suck blood until they become full and heavy and drop onto the towel. The regimen usually takes 45 to 60 minutes.

The leeches inject an anti-coagulant, so bleeding continues up to four hours after they fall off. John wears the heavy bandages to bed.

The Dunlaps carry out this unusual routine — 60 or so times since December — not because of the blood that the leeches suck from John but for what they inject: Enzyme-laden saliva.

Andrew, the Dunlaps' mentally ill son, is charged with attempted murder and domestic assault, and remains in jail awaiting trial. The couple have told authorities that they mainly want Andrew to receive mental health treatment.

He is the youngest of their four children, behind Jay, David and Jeff. The Dunlaps have experienced tragedy long before the 2015 assault.

Jeff was a St. Jude Children's Research Hospital patient who died of cancer at age 10, in September 1974.

The same book, "Resilient Grieving" by resilience researcher Dr. Lucy Hone, which states that gratitude, hope and realistic optimism are important for coping after a loss or trauma, also states that choosing what to focus on is also important.

Dunlap recalls a return car trip from Knoxville, where he and Marcia had been visiting grandchildren shortly after he was released from rehab.

"As we were driving back I started thinking of all the things I won't get to do again. In my mind, I was going down the list," he said.

It would be a long list, including some leisure activities he loves. An avid Cubs fan, he enjoyed attending spring training games in Arizona. A passionate golfer, he enjoyed watching how the ball flew when he struck it well.

But Dunlap stopped himself from completing the list of losses, telling himself, " 'You don't want to dwell on that'. . . It's as if the Lord sent me a message that hit me across my forehead, saying, 'John, get over it. It could be a whole lot worse.'

"Anytime I want to start thinking about the things I'm missing or not doing what I used to do, I think 'Get over it. Move on'."

Sudden blindness is such a change in lifestyle. "I guess some people may feel the world has ended for them, but it hasn't," he said.

The stem cell and leech therapy is expensive and not covered by health insurance. Some have expressed their skepticism about the legitimacy of the experimental treatments.

"You have some people who are concerned for you, that your approach is not going to be effective," Dunlap said.

"Yet, several folks up here have said, 'John, I'd take a shot at it. It is expensive but you're the one with the white cane and the one who is blind and has to live with it. You have everything to gain and nothing to lose'."

While some might be concerned about the unusual treatments, many others are inspired by the Dunlaps, said Blanche Tosh, a fellow church member and friend since high school.

"I have told them so many times, 'You just can't begin to know the lives you have affected," Tosh said.

"I know so many people who look at the way they are dealing with multiple things. How could anybody endure that and just go on and be pleasant and make it from day to day with the consistent attitude that the world sees.

"You are not going to find many people who ever see one of them without a smile," Tosh said.

She was inspired to start a GoFundMe account (gofundme.com/johndunlapvision) to help cover the Dunlaps' expenses. As of midweek, $8,795 of the $100,000 goal had been raised.

Since December, Dunlap has undergone two-and-a-half rounds of leech therapy and two series of stem cell treatments. The couple traveled to California in June for the most recent stem cell procedures, and returned home with stem-cell eye drops and injections.

Now they are in the middle of the leech therapy they resumed this summer.

John has a follow-up exam next week at Hamilton Eye Institute, and will learn if there's been continued progress from the stem cell and leech therapies.

The California doctor "indicated it would take two to three months to see if we were getting any results from stem cell therapy out there," Dunlap said. That time could come sometime this month or in September.

If the stem cell therapy has not worked by then, he said, "We'll just have to see what any third plan looks like, and the cost involved."

Late in life, Dunlap has been forced to learn to type, work a computer, navigate with a cane, count the steps and memorize the turns from one spot to another, communicate with Siri, and smile as bloodsucking leeches dangle from his cheeks.

Asked about his sources of inner-strength, he responded, "I don't know I'd call it inner-strength.

"I can tell you I certainly believe in the Lord. We pray daily. I appreciate the prayers of others. I think it certainly is a faith issue."

He also credits his late mother, Cora, a single parent who managed a grocery in North Memphis' Springdale neighborhood. "She was a very optimistic, loving person," he recalled.

"And I've had Marcia's support. Marcia wasn't going to let me give up, just sit down and do nothing."

The Dunlaps are starting to consider resuming their annual trips to Cubs spring training in Arizona. Maybe next spring.

"You may have your vision by then," Marcia told John.

"I might," he responded. "We'll see."