The article analyses 22 cases of severe impairment of vision to far distances for no apparent reason. Visual impairment was observed regardless of patients’ age and type of eye defect diagnosed, with the majority of people suffering from myopia and accompanying astigmatism. The exclusion of causes related to the cornea and retina, optic nerve damage and the lack of visible pathologies of the lens in the physical examination did not allow for the determination of the cause of deterioration in visual acuity to far distances despite good vision to near distances. The results of examinations using iTrace indicated the lens as the cause of visual impairment despite the apparent lack of opacity and other pathologies within it. The results of examinations in the field of Higher Order Aberration, Opacity Map, Modulation Transfer Function™ and their graphical presentation using the Dysfunctional Lens Index™ module were analysed. Low values of visual contrast sensitivity and high values of higher order aberrations for the internal optics were observed, with the correct values for the cornea. The more pathological the results of the visual contrast sensitivity and higher order aberration, the lower the values of visual acuity to far distances. In most cases removing the dysfunctional lens and replacing it with an artificial lens allowed for a significant improvement in vision to far distances while maintaining proper vision to near distances. The procedure was performed on patients over 18 years of age. The medical history in the study group may indicate a congenital nature of the abnormal structure of the lens. Thus, it is necessary to consider verification of the diagnosis made in some patients, pointing to a new disease entity, i.e. congenital lens dysfunction.
Keywords: Lens Dysfunction, Itrace, Decreased Vision, Amblyopia