While plants are able to make carotenoids de novo, humans must obtain them primarily through plant-based foods. Of the 750+ carotenoids found in nature, 40 to 50 are found in the human diet and approximately 18 are found in human blood, of which α-carotene, β-carotene, lycopene, lutein, zeaxanthin, and β-cryptoxanthin are the most common. Remarkably, the central retina (an area know as the macula that mediates central and colour vision) concentrates only 3 carotenoids lutein, zeaxanthin and meso-zeaxanthin. Meso-zeaxanthin is the strongest antioxidant of the 3 and is essential to ensure we have a full protective pigment at the macula.