Sentence:  ...attributed to the fact that infantile astigmatism can disrupt emmetropization by reducing an infant sensitivity to focusing signals, thus leading to <WSD>underaccomodation</WSD> or alignment impairment with a physiological fix of elongated eye ball [18]. 
Meaning of the word marked with <WSD> tags:  The improper adjustment of the eye muscles so that the focal point of a target image falls short of the retina.