Heavy eyelids describe that feeling when it is almost impossible to keep the eyelids open. The most common cause of this is exhaustion, especially if the levator muscles have become weakened after keeping the eyelids open all day. It is also possible for heavy eyelids to be a hereditary trait.

Ageing is another common cause of heavy eyelids as the skin can become less elastic and flexible (primarily due to a natural decrease in collagen and elastin levels). Chronic allergies and sinus infections can also exacerbate the heaviness felt, as can any excess skin found on the eyelid. Common medical conditions such as dermatochalasis, ptosis and blepharitis can also cause heavy eyelids.