Sentence:  When Cegalis measured accommodative responses to changes in convergence distance caused by ophthalmic prisms, he found that although subjects initially <WSD>under-accommodated</WSD> the target, they quickly adapted for near target distances, with no significant after-effects. 
Meaning of the word marked with <WSD> tags:  To adjust the focal point of the eye so that the image of the target falls short of the retina.