Curvatural: Curvatural hypermetropia occur when curvature of lens or cornea is flatter than normal. About 1 mm increase in radius of curvature results in 6 diopters of hypermetropia. Cornea is flatter in microcornea and cornea plana. Index: Age related changes in refractive index (cortical sclerosis) can cause hypermetropia. Another cause of index hypermetropia is diabetes. Occasionally, mild hypermetropic shift may be seen in association with cortical or subcapsular cataract also. Positional: Positional hypermetropia occur due to posterior dislocation of Lens or IOL. It may occur due to trauma. Consecutive: Consecutive hypermetropia occur due to surgical over correction of myopia or surgical under correction in cataract surgery. Functional: Functional hypermetropia results from paralysis of accommodation as seen in internal ophthalmoplegia, CN III palsy etc. Absence of lens: Congenital or acquired aphakia cause high degree hypermetropia.Far-sightedness is often present from birth, but children have a very flexible eye lens, which helps to compensate. In rare instances hyperopia can be due to diabetes, and problems with the blood vessels in the retina. Diagnosis
A diagnosis of far-sightedness is made by utilizing either a retinoscope or an automated refractor-objective refraction; or trial lenses in a trial frame or a phoropter to obtain a subjective examination. Ancillary tests for abnormal structures and physiology can be made via a slit lamp test, which examines the cornea, conjunctiva, anterior chamber, and iris.In severe cases of hyperopia from birth, the brain has difficulty in merging the images that each individual eye sees.
Legality
According to the List of Psychotropic Substances under International Control published by the International Narcotics Control Board, phendimetrazine is a Schedule III controlled substance under the Convention on Psychotropic Substances. See also

2-Phenyl-3,6-dimethylmorpholine
3-Fluorophenmetrazine
Fenbutrazate
G-130
Morazone
Manifaxine
Radafaxine
Phenmetrazine
Fenmetramide


== References ==