Dr. William Goldstein of EyeHealthWeb states that red, puffy eyes can result from fluid retention, allergies, stress or hormone changes. Additionally, he explains that crying also results in swollen eyes due to the inflammation of the small glands in the eyelids that produce tears.
Dr. Goldstein further expounds that red, puffy eyes can be attributed to excessive alcohol intake, lack of sleep or too much sodium in the diet. Red puffy eyes can also be a result of skin disorders, such as dermatitis. Other possible causes include: the normal aging process, dysfunction of tear glands, hypothyroidism, contact lenses, nephritic syndrome, blepharitis, conjunctivitis, styes and eye infections.
External swelling is typically caused by insect bites, rash, injuries, infection and natural causes, according to April Kahn of Healthline. For example, an eye infection may cause swelling around the eyes.
Dr. Melissa Conrad Stoppler of MedicineNet states that swollen eyes, also called periorbital puffiness, involve the presence of excess fluid in the connective tissues surrounding the eyes. She specifies that almost any cause of inflammation to the eye region can manifest as swelling.
The skin around the eyes is extremely thin and sensitive. Puffy eyes often go back to normal with home treatments, although sometimes puffy eyes are a symptom of certain eye conditions that need professional examination, Dr. Goldstein explains. He mentions that it is important to contact an optometrist if severe and persistent puffy eyes are accompanied by other symptoms, such as redness around the eye, blurry vision, itching, eye pain, eye discharge, discomfort, nausea or fever.