As it is associated with excessive sun or wind exposure, wearing protective sunglasses with side shields and/or wide brimmed hats and using artificial tears throughout the day may help prevent their formation or stop further growth. Surfers and other water-sport athletes should wear eye protection that blocks 100% of the UV rays from the water, as is often used by snow-sport athletes. Many of those who are at greatest risk of pterygium from work or play sun exposure do not understand the importance of protection.

The exact cause is unknown, but it is associated with excessive exposure to wind, sunlight, or sand. Therefore, it is more likely to occur in populations that inhabit the areas near the equator, as well as windy locations. In addition, pterygia are twice as likely to occur in men than women.

A pinguecula is one of the differential diagnoses for a limbal nodule. It may have an increased prevalence in Gaucher's disease.

Genetic counseling for VWS involves discussion of disease transmission in the autosomal dominant manner and possibilities for penetrance and expression in offspring. Autosomal dominance means affected parents have a 50% chance of passing on their mutated "IRF6" allele to a their child. Furthermore, if a cleft patient has lip pits, he or she has a ten times greater risk of having a child with cleft lip with or without cleft palate than a cleft patient who does not have lip pits. Types of clefting between parents and affected children are significantly associated; however, different types of clefts may occur horizontally and vertically within the same pedigree. In cases where clefting is the only symptom, a complete family history must be taken to ensure the patient does not have non-syndromic clefting.

A pinguecula is a common type of conjunctival degeneration in the eye.

Lip pits may be surgically removed either for aesthetic reasons or discomfort due to inflammation caused by bacterial infections or chronic saliva excretion, though spontaneous shrinkage of the lip pits has occurred in some rare cases. Chronic inflammation has also been reported to cause squamous-cell carcinoma. It is essential to completely remove the entire lip pit canal, as mucoid cysts can develop if mucous glands are not removed. A possible side effect of removing the lip pits is a loose lip muscle. Other conditions associated with VWS, including CL, CP, congenital heart defects, etc. are surgically corrected or otherwise treated as they would be if they were non-syndromic.

A limbal nodule is any nodular lesion at the limbus (junction of the cornea and sclera) of the eye.

The differential diagnosis for a limbal nodule can include:

- Pinguecula

- Early Pterygium

- Foreign body / foreign body granuloma

- Phlycten, an inflamed nodule of lymphoid tissue

- Episcleritis

- Scleritis

- Granuloma

- Limbal dermoid, a kind of choristoma (NB: in other organs "dermoid" can refer to a teratoma)

- malignant melanoma

Pterygium inversum unguis (also known as "Pterygium inversus unguis," and "Ventral pterygium") is characterized by the adherence of the distal portion of the nailbed to the ventral surface of the nail plate. The condition may be present at birth or acquired, and may cause pain with manipulation of small objects, typing, and close manicuring of the nail.

Hypertropia may be either congenital or acquired, and misalignment is due to imbalance in extraocular muscle function. The superior rectus, inferior rectus, superior oblique, and inferior oblique muscles affect the vertical movement of the eyes. These muscles may be either paretic, restrictive (fibrosis) or overactive effect of the muscles. Congenital cases may have developmental abnormality due to abnormal muscle structure, usually muscle atrophy / hypertrophy or rarely, absence of the muscle and incorrect placement.

Specific & common causes include:

- Superior oblique Palsy / Congenital fourth nerve palsy

- Inferior oblique overaction

- Brown's syndrome

- Duane's retraction syndrome

- Double elevator palsy

- Fibrosis of rectus muscle in Graves Disease (most commonly inferior rectus is involved)

- Surgical trauma to the vertical muscles (e.g. during scleral buckling surgery or cataract surgery causing iatrogenic trauma to the vertical muscles).

Sudden onset hypertropia in a middle aged or elderly adult may be due to compression of the trochlear nerve and mass effect from a tumor, requiring urgent brain imaging using MRI to localise any space occupying lesion. It could also be due to infarction of blood vessels supplying the nerve, due to diabetes and atherosclerosis. In other instances it may be due to an abnormality of neuromuscular transmission, i.e., Myasthenia Gravis.

A black eye, periorbital hematoma, or shiner, is bruising around the eye commonly due to an injury to the face rather than to the eye. The name is given due to the color of bruising. The so-called black eye is caused by bleeding beneath the skin and around the eye. Sometimes a black eye could get worse if not referring to a doctor after a few months, indicating a more extensive injury, even a skull fracture, particularly if the area around both eyes is bruised (raccoon eyes), or if there has been a prior head injury.

Although most black eye injuries are not serious, bleeding within the eye, called a hyphema, is serious and can reduce vision and damage the cornea. In some cases, abnormally high pressure inside the eyeball (ocular hypertension) can also result.

Strabismus can be seen in Down syndrome, Loeys-Dietz syndrome, cerebral palsy, and Edwards syndrome. The risk is increased among those with a family history of the condition.

It is a feature of Turner syndrome (only found in girls) and Noonan syndrome, as well as the rarer Klippel-Feil syndrome, or Diamond-Blackfan Anemia

Unless there is actual trauma to the eye itself (see below), extensive medical attention is generally not needed.

Applying an ice pack will keep down swelling and reduce internal bleeding by constricting the capillaries. Additionally, analgesic drugs (painkillers) can be administered to relieve pain.

An anecdotal remedy for a black eye involves the administering of raw meat to treat the condition - Research on this treatment has yet to find any evidence of this treatment being effective.

Young children with strabismus normally suppress the visual field of one eye (or part of it), whereas adults who develop strabismus normally do not suppress and therefore suffer from double vision (diplopia). This also means that adults (and older children) have a higher risk of post-operative diplopia after undergoing strabismus surgery than young children. Patients who have undergone strabismus surgery at a young age often have monofixation syndrome (with peripheral binocular fusion and a central suppression scotoma).

Hypertropia is a condition of misalignment of the eyes (strabismus), whereby the visual axis of one eye is higher than the fellow fixating eye.

Hypotropia is the similar condition, focus being on the eye with the visual axis lower than the fellow fixating eye.

Dissociated Vertical Deviation is a special type of hypertropia leading to slow upward drift of one or rarely both eyes, usually when the patient is inattentive.

On babies, webbed neck may look like loose folds of skin on the neck. As the child grows, the skin may stretch out to look like there is little or no neck.

The diagnosis of PPS has been made in several ethnic groups, including Caucasian, Japanese, and sub-Saharan African. Males and females are equally likely to suffer from the syndrome. Since the disorder is very rare, its incidence rate is difficult to estimate, but is less than 1 in 10,000.

Multiple pterygium syndrome is a cutaneous condition inherited in an autosomal dominant fashion.

Of the many causes, conjunctivitis is the most common. Others include:

"Usually nonurgent"

- blepharitis - a usually chronic inflammation of the eyelids with scaling, sometimes resolving spontaneously

- subconjunctival hemorrhage - a sometimes dramatic, but usually harmless, bleeding underneath the conjunctiva most often from spontaneous rupture of the small, fragile blood vessels, commonly from a cough or sneeze

- inflamed pterygium - a benign, triangular, horizontal growth of the conjunctiva, arising from the inner side, at the level of contact of the upper and lower eyelids, associated with exposure to sunlight, low humidity and dust. It may be more common in occupations such as farming and welding.

- inflamed pinguecula - a yellow-white deposit close to the junction between the cornea and sclera, on the conjunctiva. It is most prevalent in tropical climates with much UV exposure. Although harmless, it can occasionally become inflamed.

- dry eye syndrome - caused by either decreased tear production or increased tear film evaporation which may lead to irritation and redness

- airborne contaminants or irritants

- tiredness

- drug use including cannabis

"Usually urgent"

- acute angle closure glaucoma - implies injury to the optic nerve with the potential for irreversible vision loss which may be permanent unless treated quickly, as a result of increased pressure within the eyeball. Not all forms of glaucoma are acute, and not all are associated with increased 'intra-ocular' pressure.

- injury

- keratitis - a potentially serious inflammation or injury to the cornea (window), often associated with significant pain, light intolerance, and deterioration in vision. Numerous causes include virus infection. Injury from contact lenses can lead to keratitis.

- iritis - together with the ciliary body and choroid, the iris makes up the uvea, part of the middle, pigmented, structures of the eye. Inflammation of this layer (uveitis) requires urgent control and is estimated to be responsible for 10% of blindness in the United States.

- scleritis - a serious inflammatory condition, often painful, that can result in permanent vision loss, and without an identifiable cause in half of those presenting with it. About 30-40% have an underlying systemic autoimmune condition.

- episcleritis - most often a mild, inflammatory disorder of the 'white' of the eye unassociated with eye complications in contrast to scleritis, and responding to topical medications such as anti-inflammatory drops.

- tick borne illnesses like Rocky Mountain spotted fever - the eye is not primarily involved, but the presence of conjunctivitis, along with fever and rash, may help with the diagnosis in appropriate circumstances.

People of all ages who have noticeable strabismus may experience psychosocial difficulties. Attention has also been drawn to potential socioeconomic impact resulting from cases of detectable strabismus. A socioeconomic consideration exists as well in the context of decisions regarding strabismus treatment, including efforts to re-establish binocular vision and the possibility of stereopsis recovery.

One study has shown that strabismic children commonly exhibit behaviors marked by higher degrees of inhibition, anxiety, and emotional distress, often leading to outright emotional disorders. These disorders are often related to a negative perception of the child by peers. This is due not only to an altered aesthetic appearance, but also because of the inherent symbolic nature of the eye and gaze, and the vitally important role they play in an individual's life as social components. For some, these issues improved dramatically following strabismus surgery. Notably, strabismus interferes with normal eye contact, often causing embarrassment, anger, and feelings of awkwardness, thereby affecting social communication in a fundamental way, with a possible negative effect on self esteem.

Children with strabismus, particularly those with exotropia (an outward turn), may be more likely to develop a mental health disorder than normal-sighted children. Researchers have theorized that esotropia (an inward turn) was not found to be linked to a higher propensity for mental illness due to the age range of the participants, as well as the shorter follow-up time period; esotropic children were monitored to a mean age of 15.8 years, compared with 20.3 years for the exotropic group. A subsequent study with participants from the same area monitored congenital esotropia patients for a longer time period; results indicated that esotropic patients "were" also more likely to develop mental illness of some sort upon reaching early adulthood, similar to those with constant exotropia, intermittent exotropia, or convergence insufficiency. The likelihood was 2.6 times that of controls. No apparent association with premature birth was observed, and no evidence was found linking later onset of mental illness to psychosocial stressors frequently encountered by those with strabismus.

Investigations have highlighted the impact that strabismus may typically have on quality of life. Studies in which subjects were shown images of strabismic and non-strabismic persons showed a strong negative bias towards those visibly displaying the condition, clearly demonstrating the potential for future socioeconomic implications with regard to employability, as well as other psychosocial effects related to an individual's overall happiness.

Adult and child observers perceived a right heterotropia as more disturbing than a left heterotropia, and child observers perceived an esotropia as "worse" than an exotropia. Successful surgical correction of strabismus—for adult patients as well as children—has been shown to have a significantly positive effect on psychological well-being.

Very little research exists regarding coping strategies employed by adult strabismics. One study categorized coping methods into three subcategories: avoidance (refraining from participation an activity), distraction (deflecting attention from the condition), and adjustment (approaching an activity differently). The authors of the study suggested that individuals with strabismus may benefit from psychosocial support such as interpersonal skills training.

No studies have evaluated whether psychosocial interventions have had any benefits on individuals undergoing strabismus surgery.

Among fifth and sixth grade children convergence insufficiency is 13%. In studies that used standardized definitions of Convergence insufficiency, investigators have reported a prevalence of 4.2% to 6% in school and clinic settings. The standard definition of Convergence insufficiency is exophoria greater at near than at distance, a receded near point of convergence, and reduced convergence amplitudes at near.

A red eye is an eye that appears red due to illness or injury. It is usually injection and prominence of the superficial blood vessels of the conjunctiva, or sclera, which may be caused by disorders of these or adjacent structures. Conjunctivitis and subconjunctival hemorrhage are two of the less serious but more common causes.

Management includes assessing whether emergency action (including referral) is needed, or whether treatment can be accomplished without additional resources.

Slit lamp examination is invaluable in diagnosis but initial assessment can be performed using a careful history, testing vision (visual acuity), and carrying out a penlight examination.

Cyclotropia is a form of strabismus in which, compared to the correct positioning of the eyes, there is a of one eye (or both) about the eye's visual axis. Consequently, the visual fields of the two eyes appear tilted relative to each other. The corresponding "latent" condition – a condition in which torsion occurs only in the absence of appropriate visual stimuli – is called cyclophoria.

Cyclotropia is often associated with other disorders of strabism, can result in double vision, and can cause other symptoms, in particular head tilt.

In some cases, subjective and objective cyclodeviation may result from surgery for oblique muscle disorders; if the visual system cannot compensate for it, cyclotropia and rotational double vision (cyclodiplopia) may result. The role of cyclotropia in vision disorders is not always correctly identified. In several cases of double vision, once the underlying cyclotropia was identified, the condition was solved by surgical cyclotropia correction.

Conversely, artificially causing cyclotropia in cats leads to reduced vision acuity, resulting in a defect similar to strabismic amblyopia.

Convergence insufficiency or convergence disorder is a sensory and neuromuscular anomaly of the binocular vision system, characterized by a reduced ability of the eyes to turn towards each other, or sustain convergence.

Van der Woude syndrome (VDWS) and popliteal pterygium syndrome (PPS) are allelic variants of the same condition; that is, they are caused by different mutations of the same gene. PPS includes all the features of VDWS, plus popliteal pterygium, syngnathia, distinct toe/nail abnormality, syndactyly, and genito-urinary malformations.