Sclerocornea is an extremely rare congenital anomaly of the eye, it is considered a form of congenital corneal opacity (CCO) with no clear gender bias, in which the cornea blends with sclera, having no clear-cut boundary. The extent of the resulting opacity varies from peripheral to total (sclerocornea totalis). While the exact historical origins of its documentation are unclear, studies on sclerocornea has long been recognized in ophthalmology as a rare but significant anomaly going as far back as the 1960's. The severe form is thought to be inherited in an autosomal recessive manner, but there may be another, milder form that is expressed in a dominant fashion. In some cases the patients also have abnormalities beyond the eye (systemic), such as limb deformities and craniofacial and genitourinary defects.

According to one tissue analysis performed after corneal transplantation, the sulfation pattern of keratan sulfate proteoglycans in the affected area is typical for corneal rather than scleral tissue.

Sclerocornea may be concurrent with cornea plana.

Sclerocornea causes parts or all of the cornea to become cloudy. This cloudiness can be partial or complete. The more of the cornea that is affected, the worse a persons vision will be. The main area affected is the cornea, but the issue can also spread to nearby parts of the eye, like the limbus and front eye structure, such as the iris. Since Sclerocornea is present from birth and does not develop later in life there are no short-term symptoms or signs. The condition usually affects both eyes and it does not worsen over time, the symptoms and severity are present from birth and generally remain stable.

As a result and depending on the variety, the patient may have poor vision from birth and in some cases problems with eye movement, such as nystagmus or strabismus. Over time, people may develop severe farsightedness, glaucoma, and other eye issues.

The exact cause of Sclerocornea is not fully understood, but it is believed to involve genetics and developmental factors during fetus development. Sclerocornea can be inherited genetically, as autosomal dominant or recessive trait, with the latter form often being more severe. There are findings suggesting that a genetic locus at chromosome 22q11.2 plays a crucial role in the formation and development of the eye during the early stages of embryonic growth. This gene in some cases are associated with the genetic disorders like Digeorge syndrome, PHACES syndrome, Dandy-walker malformation, and Hurler syndrome making genetic counseling important.^{[citation needed]}

The condition is thought to occur because the neural crest cells don't move or develop correctly between the 7th and 10th week of pregnancy. These cells are important for forming many parts of the eye structures, and abnormalities in their formation can lead to issues.

Recent research has highlighted the role of mutation/deletion in the RAD21 gene. A 2019 study suggest that beyond its known role in cell division and chromosome organization, RAD21 may also contribute to the development of peripheral sclerocornea.