Carotenoids are essential fat-soluble micronutrients that are critical components of a healthy diet. Among the carotenoids, lutein and zeaxanthin, chemical isomers, are non-provitamin A carotenoids. The human body cannot synthesize them, so they must be obtained from food. Egg yolks, corn, green leafy vegetables, and algae are rich sources of these two carotenoids. Lutein and zeaxanthin are found in high concentrations in the human retina and brain, playing a critical role in vision and cognitive function. Xanthophylls, belonging to the carotenes family, are polar molecules known for filtering high-energy blue light, reducing oxidative stress and potential damage to photoreceptors and the retinal pigment epithelium. Antioxidant properties are essential for maintaining macular health, preventing age-related macular degeneration, and improving visual performance. In addition, lutein and zeaxanthin contribute to cognitive health. They cross the blood–brain barrier and have been identified in the hippocampus, cerebellum, frontal, occipital, and temporal cortices. These carotenoids are selectively taken into the brain, where they support neuronal integrity, enhance cognitive processes such as memory and learning, and may delay the onset of neurodegenerative diseases, including Alzheimer’s. Recent research suggests that high dietary intakes and serum levels of these carotenoids are associated with improved cognitive performance across the lifespan. This highlights the importance of lutein and zeaxanthin in maintaining visual and cognitive function and underscores that adequate dietary intake is vital for overall health and well-being.