A 291-day-old retina. Our ability to see colors develops in the womb. Now scientists have replicated that process, which could help accelerate efforts to cure colorblindness and lead to new treatments for diseases. Johns Hopkins University hide caption

Randy and Karen O'Burke together at their son's home in Hendersonville, Tenn., last week. "Apparently, I'm pretty much of a miracle," Randy says. Morgan Hornsby for NPR hide caption

Richard Langford, at home in East Nashville, Tenn., still has significant trouble with mental focus and memory issues 10 years after a sudden and serious infection landed him in the hospital ICU for several weeks. Morgan Hornsby for NPR hide caption

Delayed pushing made no difference in whether first-time mothers had a cesarean section, a large study finds. Getty Images hide caption

Some apps, like CBT-I Coach, use proven scientific methods to help people manage their underlying sleep challenges. Mary Mathis/NPR hide caption

Suboxone, a medicine to treat opioid addiction, helps people struggling with substance abuse by blocking their cravings and physical withdrawal symptoms. Craig F. Walker/The Boston Globe/Getty Images hide caption

Psychologists find that cognitive processing therapy — a type of counseling that helps people learn to challenge and modify their beliefs related to a trauma — can be useful in healing the mental health problems some experience after a sexual assault. Hero Images/Getty Images hide caption

Osteoporosis specialists are considering wider use of a drug to strengthen bones in elderly women. BSIP/BSIP/UIG/Getty Images hide caption

Dr. James P. Allison, University of Texas MD Anderson Cancer Center, poses for a photo in New York in 2015. Allison and Tasuku Honjo have jointly been awarded the Nobel Prize in medicine or physiology. Richard Drew/AP hide caption

For severe heart failure patients, an LVAD, or left ventricular-assist device, helps the heart pump blood. 7asmin via Wikimedia Commons hide caption

Immature human eggs (pink) were created by Japanese researchers using stem cells that were derived from blood cells. Courtesy of Saitou Lab hide caption

The fix was in for this rhesus macaque drinking juice on the Ganges River in Rishikesh, Uttarakhand, India. No gambling was required to get the reward. Fotofeeling/Getty Images/Westend61 RM hide caption

A Swiss study tracking the health of a group of children conceived via assisted reproductive technology found that a surprising number developed premature aging of their blood vessels. Now in their teens, 15 percent have hypertension. Steve Debenport/Getty Images hide caption

Megan Baker (left) of Papa & Barkley Co., a Cannabis company based in Eureka, Calif., shows Shirley Avedon of Laguna Woods different products intended to help with pain relief. Stephanie O'Neill for NPR hide caption

Aaron Reid, 20, rests in an exam room in the National Institutes of Health Clinical Center in Bethesda, Md. Rebecca Davis/NPR hide caption

Barb Williamson runs several sobriety houses in Pennsylvania, commercially run homes where residents support each other in their recovery from opioid addiction. Initially, she says, she saw the use of Suboxone or methadone by residents as "a crutch," and banned them. But evidence the medicines can be helpful changed her mind. Kimberly Paynter/WHYY hide caption

Baby boomers who use marijuana seem to be using it more often than in previous years, a recent survey finds — 5.7 percent of respondents ages 50 to 64 said they'd tried it in the past month. The drug is also gaining popularity among people in their 70s and 80s. Manonallard/Getty Images hide caption

Scientists at Johns Hopkins University are studying barn owls to understand how the brain maintains focus. Meredith Rizzo/NPR hide caption

The search for the cause of Alzheimer's has so far come up dry. Some researchers are now asking if germs play a role. Ariel Davis for NPR hide caption