Cystic fibrosis (CF) is a fairly common lethal genetic disease in whites, inherited via an autosomal recessive pattern. Several clinically evident anomalies of the eye such as xerophthalmia, papilledema, retinal alterations and optic neuropathy have been described. In the present study we investigated lens changes in 40 patients affected by CF, to relate the results to the stage of digestive insufficency. Each patient underwent an accurate ocular examination including visual acuity, slit-lamp examination, and measurement of lens transparency with the Opacity Lens Meter 701. The results were compared with those of an age- and sex-matched control group. The comparison between the lens opacity values obtained in the CF patients and those measured in the control group showed a statistically significant difference; moreover, lens transparency was more decreased in patients with severe digestive insufficiency.