Conjunctivitis is an inflammatory disease of the eye caused by bacterial, viral, fungal, and mycoplasma-chlamydia infections. The main clinical manifestations are conjunctival congestion, eye pain, photophobia, lacrimation, foreign body sensation, and often an increase in eye discharge. Of course, the clinical presentation varies slightly depending on the infecting agent. Bacterial conjunctivitis, usually acute in onset, is characterized by a yellow or pus-yellow discharge from the eye that is thick and sticky. It may also cause swelling and pressure in the preauricular lymph nodes. Viral conjunctivitis, which is characterized by a foreign body sensation in the eye, often involves the cornea and causes corneal irritation (pain, photophobia, eyelid spasms), and the discharge from the eye is often white, thin, and aqueous. The clinical presentation of conjunctivitis varies depending on the severity of the lesion. In milder cases of conjunctival inflammation, conjunctival congestion may be mild and primarily superficial. In more severe cases, the conjunctival congestion may be more severe and may manifest as ciliary or mixed congestion if the lesion spreads from the conjunctiva to the cornea without timely treatment. The clinical manifestations of conjunctival inflammation are not only related to the causative agent, but also to the individual’s constitution. The same type of conjunctivitis may manifest differently in different individuals, some may manifest conjunctival congestion, while others may manifest only photophobia, tearing, and foreign body sensation. In summary, regardless of the type of conjunctivitis, the common clinical presentation is conjunctival congestion often accompanied by ocular discharge.