why eating carrots is important for good vision?
Because of the beta carotene.
They are high in Vitamin A, which helps eyesight.
See
http://www.allaboutvision.com/nutrition/vitamin_a.htm
Eating carrots only improves eyesight if a person has a Vitamin A deficiency. Most people in the developed world have sufficient Vitamin A, so eating carrots doesn't help their vision.
http://www.snopes.com/food/ingredient/carrots.asp
http://healthlibrary.epnet.com/GetContent.aspx?token=0d429707-b7e1-4147-9947-abca6797a602&chunkiid=156972
http://www.webmd.com/diet/carrots-good-for-eyes
Eating carrots is often associated with promoting good vision, primarily due to their high beta-carotene content. Beta-carotene is converted in the body into vitamin A, which plays a crucial role in maintaining eye health.
To understand the link between carrots and good vision, it's important to know how the human eye functions. The retina, located at the back of the eye, contains cells called photoreceptors that are responsible for converting light into electrical signals, which are then transmitted to the brain for interpretation. There are two types of photoreceptors: rods and cones. Cones are responsible for color vision and detailed visual acuity, while rods help with vision in low-light conditions.
Vitamin A is essential for the functioning of these photoreceptor cells. It helps maintain the integrity of the outer segments of both rods and cones, enabling them to capture light effectively and transmit signals to the brain. Additionally, vitamin A is involved in the production of rhodopsin, a pigment found in the rods that enhances vision in dim light.
Carrots are an excellent source of beta-carotene, a pigment responsible for their orange color. In the body, beta-carotene is converted into vitamin A. By consuming carrots or other foods rich in beta-carotene, you provide your body with a precursor that can be transformed into vitamin A to support optimal eye health.
It's worth mentioning that while carrots can contribute to good vision, they are not the sole factor. A balanced diet that includes a variety of fruits, vegetables, and foods rich in other essential nutrients like vitamins C and E, zinc, and omega-3 fatty acids is crucial for maintaining overall eye health.
To ensure good vision, it is also important to visit an eye-care professional regularly for comprehensive eye exams.