The Hudson-Stahli line. II: A comparison of properties in eyes with and without long-term contact lens wear.

The eyes of 98 long-term contact lens wearers and 342 subjects not wearing contact lenses were examined for the presence of Hudson-Stahli lines, using slit-lamp biomicroscopy. The period of contact lens wear ranged from 2 to 25 years, all subjects using contact lenses for refractive reasons only. The incidence of Hudson-Stahli lines in contact lens wearers was not significantly different from that of control subjects in the same decades. Contact lenses appear, however, variably to alter the characteristics of the Hudson-Stahli line. Results from a group of 4 unilateral lens wearers, from 94 bilateral lens wearers and from studies of the morphology of the line suggest that contact lens wear is associated with a relative reduction of length and density of the line and also with a broadening and, more rarely, displacement of it. In eyes with brown or green irides, the attenuation of length and density by contact lens wear obscures the normal increases seen with age; in this subgroup of contact lens wearers, both factors appear to be almost constant from the third to sixth decades of life.