* There are not enough studies that talk about the benefits of onions for the eyes in particular, but garlic and onions can help improve vision, and maintain eye health.  This is because they contain the element sulfur necessary for the health of the lens of the eye, and we mention the following other general benefits of onions:

 Maintaining heart health: Many studies have shown the effect of onions in maintaining heart health and reducing risk factors for heart disease.  Such as: high blood pressure, triglyceride and cholesterol levels, in addition to reducing the level of inflammation;  This is because it contains antioxidants and compounds that prevent infections.

 - Fighting cancer: Studies have shown the effect of eating onions and garlic in preventing the growth of tumors and reducing the risk of many types of cancer.  Examples: stomach, colon, rectal, lung and ovarian cancer.  And that is because they contain sulfur compounds, and flavonoid antioxidants (English: Flavonoid antioxidants).

 - Control of blood sugar: one of the studies conducted on 42 people with type 2 diabetes showed the effect of eating 100 grams of red onions in lowering blood sugar by 40 mg / dL after 4 hours of eating.  This is because it contains sulfur compounds, and quercetin, which interacts with cells of the small intestine and pancreas to help control blood sugar regulation.

 Bone health: Studies have shown the effect of onions in increasing bone mineral density, reducing oxidative stress, enhancing levels of antioxidants, thus reducing bone loss, and preventing osteoporosis (English: Osteoporosis).  Damages of onions It is safe to eat onions in the quantities found in food, and onion extract is safe for many people, but there is not enough information on the correctness of consuming onion extract as a medicine for pregnant and breastfeeding women,

 It is advised not to take onions in medicinal quantities at least two weeks before the surgery.  Because it slows down blood clotting, which may cause bleeding during the operation, and in addition, it may cause some side effects for many people.  Such as: skin irritation or eczema.  Indigestion, increased stomach pain.  Lowering blood sugar.  The nutritional value of onions The following table explains the nutrients present in 100 grams of raw onions:

 Nutritional component Nutritional value Water 89.11 grams Calories 40 calories Protein 1.1 grams Fat 0.1 grams Carbs 9.34 grams Calcium 23 milligrams Magnesium 10 milligrams Phosphorous 29 milligrams Potassium 146 milligrams Sodium 4 milligrams