There are many causes of ocular edema: 1. acute conjunctivitis, which can cause ocular edema due to inflammatory stimulation in acute conjunctivitis. 2. acute rapid-onset allergic reactions can lead to ocular edema, bulbar conjunctival edema, and itching of the eyes. 3. lacrimal gland prolapse, which can lead to eyelid edema when the lacrimal gland prolapses, manifesting as chronic eyelid edema that is progressively more severe, and which has certain characteristics 4. nephrogenic eyelid edema, which can lead to soft tissue edema of the eyelid when the kidneys are not functioning properly. 5. mucinous edema, such as hypothyroidism, can also lead to eyelid edema. Therefore, when eyelid edema occurs, you should visit a regular eye care provider to determine the cause of the eyelid edema and treat it accordingly.