Category: Refractive defects of the eye

Amblyopia is a disorder of the visual system that is characterized by poor or indistinct vision in an eye that is otherwise physically normal. It is estimated that is affects 1-5 % of the population. The disorder is caused by impaired transmission or lack of transmission of visual image into the brain in the period […]

Strabismus or squinting is a disorder of the position of eyes and visual function, at which it is not possible to direct both visual lines towards a fixed point. Normally, when an object is observed, images of both eyes fall simultaneously into the point of central vision of the eye. However, if both eyes are […]

Astigmatism is a condition in which the light rays do not refract equally in all meridians of the eye. For the purpose of division, two imaginary meridians of the eye are defined, perpendicular to each other. The term astigmatism is of Greek origin and it literally means “no point”. At spherical lens, where all the […]

Presbyopia is the occurrence of weak vision at close range, which occurs between the ages of 40 and 45 when because of senile changes and loss of elasticity of the lens, accommodation strength of eyes weakens. Then the closest point of vision with the maximum of accommodation digresses from eyes for more than 33 cm. […]

A hypermetropical eye has weaker refractive strength than a normal eye (refractive hypermetropia), or it is too short (axial hypermetropia), so the image in it appears behind the retina. Uncorrected hypermetrope has to accommodate all the time in order to see clearly. Therefore, hypermetropes with smaller fallacy can see clearly at a distance. Hypermetropes whose […]

Shortsightedness or myopia is a condition in which light rays focus in front of the retina, instead of directly on the surface of it, causing shortsighted people to squint in order to get a sharp image of an object. To shortsighted people distant objects appear blurry, but they see close objects relatively clearly. The sign […]