Conjunctivitis (Pink Eye): This is the most common cause of red, swollen eyes with discharge. It can be viral, bacterial, or allergic in nature. The presence of "gunk" suggests a bacterial or viral infection, which is highly contagious and common.

Blepharitis: An inflammation of the eyelids that can cause redness, swelling, and discharge. It's often associated with skin conditions like acne or eczema.
Dry Eye Syndrome: Although it might seem counterintuitive, severe dry eye can lead to inflammation and a sensation of having something in the eye, which might be mistaken for "gunk."
Allergic Conjunctivitis: Seasonal or environmental allergies can cause conjunctivitis, leading to red, itchy, and watery eyes, possibly with a stringy discharge.

Acute Angle-Closure Glaucoma: A medical emergency that can present with red, painful eyes, blurred vision, and possibly nausea and vomiting. The "gunk" might be minimal, but the condition requires immediate attention to prevent vision loss.
Keratitis: An infection of the cornea that can cause pain, redness, and discharge. It's particularly dangerous because it can lead to corneal ulcers and vision loss if not treated promptly.
Orbital Cellulitis: An infection of the tissues surrounding the eye, which can cause swelling, redness, and possibly discharge. It's a serious condition that can lead to complications like abscess formation or cavernous sinus thrombosis if not treated aggressively.

Trachoma: A chronic infection of the eye caused by Chlamydia trachomatis, leading to repeated episodes of conjunctivitis and potentially causing blindness if not treated. It's rare in developed countries but more common in areas with poor sanitation and hygiene.
Gonococcal Conjunctivitis: A severe form of conjunctivitis caused by Neisseria gonorrhoeae, which can lead to rapid vision loss if not treated promptly. It's more common in newborns (acquired during birth) but can also occur in adults.