There is always a transparent, thread-like substance on the eyeball.

Under normal circumstances, the presence of transparent filamentous substances on the eyeball may be caused by factors such as dry eye syndrome, allergic conjunctivitis, or dacryocystitis. Patients can receive symptomatic treatment based on the specific cause. Detailed analysis is as follows:

1. Dry Eye Syndrome: Prolonged use of computers, smartphones, and other electronic screens can reduce blinking frequency, leading to eye dryness and triggering dry eye syndrome. Symptoms include dryness, stinging discomfort, blurred vision, eye redness and swelling, and yellowish discharge from the eyelids. Patients may use medications such as sodium hyaluronate eye drops or Yanggan Mingmu tablets under medical guidance, while also avoiding prolonged smartphone use.

2. Allergic Conjunctivitis: Exposure to allergens such as pollen, dust mites, or mold may trigger an allergic reaction, causing excessive tear production containing transparent, sticky secretions, along with symptoms like eye congestion and redness. Patients may use medications such as sodium cromoglicate eye drops or olopatadine hydrochloride eye drops under medical supervision, while also avoiding contact with known allergens.

3. Dacryocystitis: Bacterial infection of the lacrimal sac may cause inflammation, obstructing tear drainage and resulting in transparent filamentous discharge on the eye surface, accompanied by symptoms such as eye redness, swelling, and pain. Patients may be treated with medications such as minocycline hydrochloride capsules or erythromycin eye ointment under a doctor's guidance, while also avoiding rubbing the eyes with dirty hands.

In addition to the above three causes, other conditions such as keratitis, iridocyclitis, or vitreous hemorrhage could also be responsible. It is recommended that patients seek timely medical evaluation and treatment.