Researchers have grown human retinas in a petri dish, revealing how an offshoot of vitamin A plays a crucial role in generating specialised cells responsible for humans’ ability to see millions of colours. Published in PLOS Biology, the study sheds light on colour blindness, age-related vision loss, and other diseases linked to photoreceptor cells. Contrary to previous beliefs, the research indicates that retinoic acid, not thyroid hormones, determines whether cone cells specialise in sensing red or green light.
The timing of retinoic acid production during early development significantly influences cone cell differentiation. By tracking genetic differences in cone cells over time, the study provides insight into the intricate process of colour vision development.