The inner lower eyelid/conjunctiva looks markedly red and swollen. This can happen with irritation, allergy, conjunctivitis, a foreign body, or less commonly a more serious eye problem. A photo cannot diagnose the cause.

Get urgent same-day eye care if there is eye pain, light sensitivity, blurred/reduced vision, marked discharge, injury/chemical exposure, contact-lens use, or worsening swelling/redness. Sudden vision change or severe pain warrants emergency care.

Until assessed: do not rub it, stop contact lenses and eye makeup, wash hands, use a cool clean compress, and avoid using antibiotic or steroid eye drops unless prescribed.

What would you like me to assess from the photo, for example redness, swelling, possible causes, or how urgently it needs examination?

It looks like inflamed, swollen inner lower-eyelid tissue, called the palpebral conjunctiva. This is most consistent with conjunctivitis or conjunctival irritation/swelling. The swelling itself is sometimes called chemosis. A photo cannot tell whether the trigger is viral, bacterial, allergy, a trapped irritant, or an eyelid-gland problem. Conjunctivitis is a common cause of a red eye, while chemosis means conjunctival edema. Textbook of Family Medicine 9e, p. 2226; Tintinalli's Emergency Medicine, p. 112.

Because it is quite red and prominent, arrange a same-day optometrist/ophthalmologist or urgent-care assessment, especially if it is new or worsening.

Go urgently today or to emergency care if you have:

Until seen: do not rub or keep pulling the lid down, do not wear contacts or eye makeup, use a cool clean compress, and avoid steroid eye drops unless an eye clinician prescribes them.