Ms Ashmita Maden

Accommodative astigmatism (AA) is the phenomenon of compensating total astigmatism of the eye (corneal and lenticular)with the active participation of an accommodation. The astigmatic error cannot be uncovered and the proper cylinder prescribed without the use of cycloplegic because of the presence of a certain amount of physiological astigmatism in the crystalline lens produced by the action of ciliary muscles which tends to correct corneal astigmatism.

AA is usually neglected in our daily routine of the eye examination. Understanding its impact on human eyes is very important for enhancing their everyday life.

It is categorised into lenticular and corneal

Lenticular astigmatism occurs if there is a refractive error due to crystalline lens while compensating total astigmatism (distortion of the lens acts as compensating factor)

Corneal astigmatism occurs if the refractive error is due to distortion of the cornea (crystalline lens acts as aggravating factor)

Accommodative astigmatism can lead mild to severe headache causing pain around the globe of eyes. Whenever excessive near work increases the tendency of an oblique muscle to function normally gets spasm. Now, visual cortex which is responsible for sending visual information starts to reject the information for depth perception of a distant object. Eyes start to make a distant object into focus with multiple efforts which cause misalignment of the rectus muscles. It directly brings corneal astigmatism and indirectly lenticular astigmatism while trying to overcome with sectional accommodation of the crystalline lens.

There are several reasons for headache, eyestrain. Most of Eye care professionals look for binocular abnormality and check for Near point of convergence (NPC), Near the point of accommodation( NPA )as usual basis. However, it is also necessary to look for astigmatism in Aasthenopic symptoms. We should also perform cycloplegic refraction in order to be sure for not missing accommodative astigmatism.

The lens can and does accommodate astigmatically and therefore in many cases (Where accommodation is active) overcomes in part existing corneal astigmatism. This can be the reason many occupations which have excessive near work tends frequently change of glasses and mostly does not accept prescribed power in the initial stage.

A maximum number of students at the age of 9-16 finds it difficult to adjust with a given astigmatic power and complain about getting the throbbing sensation after use of prescribed glasses. Whenever there is the difficulty for accepting given power it’s necessary to ‘plea for cycloplegia’, must perform cycloplegic refraction.

Conclusively, for any Aasthenopic symptoms patient, we should carefully look for astigmatism and doing cycloplegic refraction also be taken as a primary concern.

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