Dry Eye Syndrome: This condition is characterized by insufficient lubrication of the eyes, leading to irritation, redness, and a burning sensation, especially in the morning due to prolonged eye closure during sleep which can exacerbate dryness.

Allergic Conjunctivitis: Allergies can cause eye irritation, including burning, especially in the morning after exposure to allergens like dust mites in pillows or pet dander.
Blepharitis: Inflammation of the eyelids can lead to burning sensations under the eyes, particularly in the morning due to overnight accumulation of debris and secretions.
Environmental Irritants: Exposure to smoke, pollution, or chemical fumes can irritate the eyes, causing a burning sensation that may be more noticeable in the morning.

Acute Angle-Closure Glaucoma: Although less common, this condition is an emergency and can present with severe eye pain, blurred vision, and possibly a burning sensation, though it's more typically associated with severe pain and vision changes.
Orbital Cellulitis: An infection of the tissues surrounding the eye, which can cause pain, swelling, and redness, including a burning sensation under the eyes, and requires prompt medical attention.
Sjögren's Syndrome: An autoimmune disorder that can cause dry eyes among other symptoms, and while less common, it's important not to miss due to its systemic implications.

Thygeson's Superficial Punctate Keratitis: A condition causing small, superficial lesions on the cornea, leading to eye irritation and possibly a burning sensation.
Erythema Multiforme: A skin condition that can affect the eyes, causing irritation and possibly a burning sensation, though it's relatively rare and usually associated with other systemic or dermatological findings.
Trachoma: A chronic infection of the eye caused by Chlamydia trachomatis, leading to inflammation of the conjunctiva, which can cause burning sensations among other symptoms, more common in certain geographic areas or populations.