Causes of epiphora are any that cause either overproduction of tears or decreased drainage of tears, resulting in tearing onto the cheek. This can be due to ocular irritation and inflammation (including trichiasis and entropion) or an obstructed tear outflow tract which is divided according to its anatomical location (i.e. ectropion, punctal, canalicular or nasolacrimal duct obstruction). The latter is often due to aging (a spontaneous process), conjunctivochalasis, infection (i.e. dacryocystitis), rhinitis, and in neonates or infants, failure of the nasolacrimal duct to open. Another cause could be poor reconstruction of the nasolacrimal duct system after trauma to the area. Cause of trauma could be facial fractures (including nasoethmoid fractures or maxillary Le Fort fractures), and soft tissue trauma involving the nose and/or the eyelid.

This condition is often frustrating or irritating. A systematic review studying the usage of punctal plugs for treatment of dry eye reported a few cases of epiphora among participants.

Because the disorder often occurs in people with typical dry eye symptoms, it can be difficult to distinguish readily the discomfort caused by the dry eye from that directly related to the redundant conjunctiva.

Most conjunctivochalasis is thought to be caused by both a gradual thinning and stretching of the conjunctiva that accompanies age and a loss of adhesion between the conjunctiva and underlying sclera due to the dissolution of Tenon's capsule. The resulting loose, excess conjunctiva may mechanically irritate the eye and disrupt the tear film and its outflow, leading to dry eye and excess tearing. A correlation may also exist between inflammation in the eye and conjunctivochalasis; though it is unclear if this correlation is causal. Conjunctivochalasis may be associated with previous surgery, Blepharitis, Meibomian Gland Disorder (MGD), Ehlers-Danlos Syndrome, and Aqueous Tear Deficiency,

Epiphora is an overflow of tears onto the face. A clinical sign or condition that constitutes insufficient tear film drainage from the eyes in that tears will drain down the face rather than through the nasolacrimal system.

In the United States, the incidence of primary congenital glaucoma is about one in 10,000 live births. Worldwide, the incidence ranges from a low of 1:22,000 in Northern Ireland to a high of 1:2,500 in Saudi Arabia and 1:1,250 in Romania. In about two-thirds of cases, it is bilateral. The distribution between males and females varies with geography. In North America and Europe it is more common in boys, whereas in Japan it is more common in girls.

- Congenital glaucoma

- Incidence: one in every 10000-15000 live births.

- Bilateral in up to 80% of cases.

- Most cases are sporadic (90%). However, in the remaining 10% there appears to be a strong familial component.

Untreated glaucoma leads to total blindness. Surgical treatment is required. Presently-utilized surgical procedures include goniotomy, trabeculotomy, or trabeculectomy.

Esophoria is an eye condition involving inward deviation of the eye, usually due to extra-ocular muscle imbalance. It is a type of heterophoria.

Causes include:

- Refractive errors

- Divergence insufficiency

- Convergence excess; this can be due to nerve, muscle, congenital or mechanical anomalies.

Unlike esotropia, fusion is possible and therefore diplopia is uncommon.

Crooke’s glass is a prophylactic aid consisting of a spectacle lens combined with metallic oxides to absorb ultraviolet or infrared rays and should be used by those who are prone to exposure e.g. Welding workers, cinema operators.

Entropion is a medical condition in which the eyelid (usually the lower lid) folds inward. It is very uncomfortable, as the eyelashes continuously rub against the cornea causing irritation. Entropion is usually caused by genetic factors. This is different from when an extra fold of skin on the lower eyelid causes lashes to turn in towards the eye (epiblepharon). In epiblepharons, the eyelid margin itself is in the correct position, but the extra fold of skin causes the lashes to be misdirected. Entropion can also create secondary pain of the eye (leading to self trauma, scarring of the eyelid, or nerve damage). The upper or lower eyelid can be involved, and one or both eyes may be affected. When entropion occurs in both eyes, this is known as "bilateral entropion." Repeated cases of trachoma infection may cause scarring of the inner eyelid, which may cause entropion. In human cases, this condition is most common to people over 60 years of age.

Entropion has been documented in most dog breeds, although there are some breeds (particularly purebreds) that are more commonly affected than others. These include the Akita, Pug, Chow Chow, Shar Pei, St. Bernard, Cocker Spaniel, Boxer, English Springer Spaniel, Welsh Springer Spaniel, Labrador Retriever, Cavalier King Charles Spaniel, Neapolitan Mastiff, Bull Mastiff, Great Dane, Irish Setter, Shiba Inu, Rottweiler, Poodle and particularly Bloodhound. The condition is usually present by six months of age. If left untreated, the condition can cause such trauma to the eye that it will require removal.

Entropion has also been seen in cat breeds. Typically it is secondary to trauma, or infection leading to chronic eyelid changes. It is also seen secondary to enophthalmos. Congenital cases are also seen with the brachicephalic breeds being over represented.

Upper lid entropion involves the eyelashes rubbing on the eye, but the lower lid usually has no eyelashes, so little or no hair rubs on the eye. Surgical correction is used in more severe cases. A number of techniques for surgical correction exist. The Hotz-Celsus technique involves the removal of strip of skin and orbicularis oculi muscle parallel to the affected portion of the lid and then the skin is sutured.

Alternative techniques such as the Wyman technique focus on tightening the lower eyelid, this technique is not as effective in cases of enophthalmos.

Shar Peis, who often are affected as young as two or three weeks old, respond well to temporary eyelid tacking. The entropion is often corrected after three to four weeks, and the sutures are removed.

Primary juvenile glaucoma is glaucoma that develops due to ocular hypertension and is evident either at birth or within the first few years of life. It is caused due to abnormalities in the anterior chamber angle development that obstruct aqueous outflow in the absence of systemic anomalies or other ocular malformation.

Buphthalmos (plural: buphthalmoses) is enlargement of the eyeball and is most commonly seen in infants and young children. It is sometimes referred to as buphthalmia (plural buphthalmias). It usually appears in the newborn period or the first 3 months of life. and in most cases indicates the presence of congenital (infantile) glaucoma, which is a disorder in which elevated pressures within the eye lead to structural eye damage and vision loss.

Keratopathy is common in older people. Keratopathy occurs after cataract surgery, its incidence has decreased since the advent of intraoperative viscoelastic agents that protect the endothelium.

Involutional stenosis is probably the most common cause of NLD obstruction in older persons. It affects women twice as frequently as men. Although the inciting event in this process is unknown, clinicopathologic study suggests that compression of the lumen of the NLD is caused by inflammatory infiltrates and edema. This may be the result of an unidentified infection or possibly an autoimmune disease.

The following may provide relief:

- Cold compresses

- Pad and bandage with antibiotics drops for 24 hours, heals most of the cases

- anaesthetic drops should not be used

- Oral analgesics if pain is intolerable

- Single dose of tranquilizers

Sinus disease often occurs in conjunction with, and in other instances may contribute to the development of NLD obstruction. Patients should be asked about previous sinus surgery, as the NLD is sometimes damaged when the maxillary sinus ostium is being enlarged anteriorly.

Exophoria can be caused by several factors, which include:

- Refractive errors - distance and near deviation approximately equal.

- Divergence excess - exodeviation is more than 15 dioptres greater for distance than near deviation.

- Convergence insufficiency - near exodeviation greater than distance deviation.

These can be due to nerve, muscle, or congenital problems, or due to mechanical anomalies. Unlike exotropia, fusion is possible in this condition, causing diplopia to be uncommon.

Disease begins with vesicles that coalesce. There is severe progressing edema and rupture may occur in 24 hours or less.

Dacryocystitis is an infection of the lacrimal sac, secondary to obstruction of the nasolacrimal duct at the junction of lacrimal sac. The term derives from the Greek "dákryon" (tear), "cysta" (sac), and "-itis" (inflammation). It causes pain, redness, and swelling over the inner aspect of the lower eyelid and epiphora. When nasolacrimal duct obstruction is secondary to a congenital barrier it is referred to as dacrocystocele. It is most commonly caused by "Staphylococcus aureus" and "Streptococcus pneumoniae". The most common complication is corneal ulceration, frequently in association with "S. pneumoniae". The mainstays of treatment are oral antibiotics, warm compresses, and relief of nasolacrimal duct obstruction by dacryocystorhinostomy.

About 60 percent of initial attacks of dacryocystitis will recur. Individuals with a poorly functioning immune system (immunocompromised) may develop orbital cellulitis, which may lead to optic neuritis, proptosis, motility abnormalities, or blindness.

In the recessive form corneal clouding is observed at birth or within the neonatal period, nystagmus is often present, but no photophobia or epiphora is seen. In the autosomal dominant type corneal opacification is usually seen in the first or second year of life and progresses slowly, and nystagmus is infrequently seen.

Late congenital syphilitic oculopathy is a disease of the eye, a manifestation of late congenital syphilis. It can appear as:

- Interstitial keratitis – this commonly appears between ages 6 and 12. Symptoms include lacrimation and photophobia. Pathological vascularization of the cornea cause it to turn pink or salmon colored. 90% of cases affect both eyes.

- Episcleritis or scleritis – nodules appear in or overlying the sclera (white of eye)

- Iritis or iris papules – vascular infiltration of the iris causes rosy color change and yellow/red nodules.

- Chorioretinitis, papillitis, retinal vasculitis – retinal changes can resemble retinitis pigmentosa.

- Exudative retinal detachment

Congenital syphilis is categorized by the age of the child. Early congenital syphilis occurs in children under 2 years old, and late congenital syphilis in children at or greater than 2 years old. Manifestations of late congenital syphilis are similar to those of secondary syphilis and tertiary syphilis in adults.

Accommodative insufficiency (AI) involves the inability of the eye to focus properly on an object. AI is generally considered separate from presbyopia, but mechanically both conditions represent a difficulty engaging the near vision system (accommodation) to see near objects clearly. However, AI is the term used for a patient where normal near vision is expected, whereas presbyopia is specifically the loss of accommodation due to age. Approximately 80 percent of children diagnosed with convergence excess also demonstrate AI, a relationship attributed to the accommodative convergence.

Exophoria is particularly common in infancy and childhood, and increases with age.

Congenital hereditary corneal dystrophy (CHED) is a form of corneal dystrophy which presents at birth.