Dividing of hyperopia

Hyperopia (farsightedness - hypermetropia) can be divided to axial or systemic according to the cause of the creation, ergo origin or in term of a connection to emmetropia.

Axial hyperopia

The most common type of farsightedness. It is created in consequence of incorrect, respectivelly deficient anterodorsal lenght of the eye. The eye is shorter than the refractive system requires for the precise impact of the light rays onto the retina and creating the perfect image.

Systemic (refractive) hyperopia

Systemic hyperopia is mentioned when the anterodorsal lenght of the eye is even about 24 mm, but the vergency of the eye is of a lesser value than is physiologically given ...

The radius form is a type of refractive hyperopia, which rests in radius of curvature of particular functional surfaces. They are bigger than in the case of emmetropic eye and it causes that the cornea is flatter and light rays are less refracted.

The index form is caused by a significant decrease of the refractive index of the eye optical media. This state is caused by the lack of rays refraction. It befalls older people, when moving of the eye lens to the back (congenital, by injury), when the removal of the lens or its natural absence from the birth.

According to the ability of the eye to compensate its own disorder with the help of accommodation, hyperopia can be divided to latent and manifest.

Latent hypermetropia (hyperopia latens)

It is permanently compensated by a physiological strain of accommodative apparatus of the eye. It is also called “hidden” that is a consequence of a man unaware of it because causing no problems to him. It’s value is maximum +1D.

Each of us has this physiological disorder in a way, due to which we are able to correct night myopia. It befalls mostly the young hypermetropes, when the lens is still elastic enough.

Manifest hypermetropia (hyperopia manifesta)

In other words, it is an apparent farsightedness. It cannot be overlooked because its badges of astenopic problems. It consists of two parts: facultative and absolute hypermetropia.

Facultative hypermetropia

Facultative hypermetropia is a part of manifest hypermetropia, which is overcome by an increased activity of the ciliary muscle.

Absolute hypermetropia

Absolute hypermetropia is a so big part of manifest hypermetropia that it can not be corrected either by maximum accommodation.

Total hypermetropia

Total hypermetropia (hyperopia totalis) is given by the sum of latent and manifest hypermetropia. It can be identifyied only in cycloplaegia, in the state, when the ciliary muscle is paralytic. This can be achieved by dripping eye drops called cycloplaegica.

Hypermetropia can sometimes be divided by the amount of disorder to low, medium and high.

• Low hypermetropia: to + 3 diopters
• Medium hypermetropia: +3,25 - +5 diopters
• High hypermetropia: higher than +6 diopters

Other forms of hypermetropia

Pathological farsightedness (hyperopia)

Under the term “pathological” hypermetropia we understand that this refractive disorder has another reason of its creation than the deviation in refractive system or in the lenght of the eye. It is caused secondarily by the effect of abnormal anatomy of the eye disease or injury. For instance: by the deficient eye development in prenatal and early postnatal period, chorioretinal and orbital inflammations, neoplasm, etc.

Many of developing disabilities and syndromes are associated with high hypermetropia (albinism, aniridia, Down syndrome,...). It can occur at any age.

Transit farsightedness (hyperopia)

It is a transient, temporary hypermetropia and arises as an consequence of administering certain drugs.