(NewsNation)  — An offshoot of vitamin A creates the cells that allow people to see a wide range of colors that dogs, cats and other mammals cannot, new research suggests.

A study published last week out of Johns Hopkins University used lab-grown human retinas to better understand color blindness, age-related vision loss and other diseases.

Researchers found that a molecule called retinoic acid determines whether a cone – a photoreceptor cell in the retina – is better at sensing red or green light, according to Science Daily. Only humans and their closely related primate cousins develop the red sensor, but not even all monkeys, for example, experience color the same, according to National Geographic.

Those kinds of variations in sight might create different survival advantages.

Ongoing research from Johns Hopkins labs could help scientists understand diseases including macular degeneration.

Although that goal could take some time, knowing researchers can produce those different cell types is “very, very promising,” author Robert Johnston, an associate professor of biology, told Science Daily.