PMMA lenses worn for twenty years.

In this study of 150 eyes (75 patients) wearing PMMA lenses for at least twenty years, most patients experienced only small change in corneal curvature. Some developed with-the-rule astigmatism, but 27% showed no variations in corneal toricity, although a refractive change of +/- 3.00 D was observed. 40 eyes had no difference of cylinder Rx and 13 maintained the same spherical correction. Graphs indicate a limited spread of statistically significant changes in the corneal curvature. Complete information on corneal integrity is not included in this study but biomicroscopic examination did not disclose any serious adverse conditions in the opinion of the authors.

A hard lens with extended wear possibilities.

The variety of parameters affecting extended wear lenses makes it obvious that the ability to use a lens under an eye closed in sleep is by no means solely contingent upon the oxygen transmission characteristics of the material. This study shows that a new silicone acrylate lens apparently permits sufficient tear-flow to maintain a viable cornea while the lens is worn overnight. In this preliminary report, over eighty percent of the previously successful hard lens patients fitted with lenses made of this material were able to maintain contact lens wear on an extended basis.

An evaluation of the Cavitron Autorefractor 7 with contact lenses and non contact lens wearing patients.

The Autorefractor 7 is a microcomputor assisted electro-mechanical optical system recently introduced to the professions for the subjective measurement of refractive error, phorias, and accommodative capacity. In this study of 450 eyes, 150 were wearing hard contact lenses, 150 wearing soft lenses, and 150 habitually wore a spectacle correction. Comparisons involved only the subjective refractive feature of the instrument and indicated no predictable difference in the three groups. Comparison of the Autorefractor 7 and clinical subjective refraction with the phoropter, however, showed that the instrument is reliable in the majority of cases but has a tendency to overcorrect myopia and astigmatism.

Utilization of paraoptometrics in contact lens practice.

The author discusses the many types of paraoptometrics used in a busy contact lens practice and how to integrate them into a professional team that offers quality care in a well-managed practice.

Cosmetic contact lenses in the care of the child.

As their name implies, cosmetic contact lenses are used to hide or cover blemishes or disfigurements of the iris, cornea, or sclera. A wide variety of options are available to the optometrist in attempting to aid a child with an ocular disfigurement. The customized artist-painted scleral shell is ideal in many cases, but a surprising number of defects can be adequately camouflaged with corneal lenses presently available from laboratories. The future use of cosmetic soft lenses is promising, and since many conditions involving the need for optical correction are capable of provoking future visual disorders, infants today can look forward to better vision when a cosmetic contact lens is fitted early in life.

The relationship of age, keratometry, and miscellaneous physiological factors in hydrogel lens wear.

A retrospective study of 94 soft contact lens patients was performed to determine the relationship of a number of physiological and lens-fitting characteristics. Results yielded only medium to low relationships, the highest correlation being between age, Schirmer, and K readings. Persons with dry and excessively mucoid eyes were found to be older and to have flatter corneas and lower Schirmer results. Older patients also tended to have more acidic tears and a shorter tear film breakup time. The group was studied from three aspects: (1) as a whole to establish means, (2) the relationship of physiological conditions, and (3) the relationship to hydrogel lens surface coating.

Do patients really want cheap lenses?

There is a strong possibility that many patients perceive newspaper advertisements as a sign of dependability or prestige rather than the evidence of unethical behavior that professionals traditionally frown upon. "Confidence in the doctor" was the foremost reason given for seeking professional service in a survey by a major commercial optical corporation. Two hundred fifty patients interviewed in a contact lens practice agreed, and the tabulated results would indicate that price alone is not a major factor.

Contact lenses for the graying American.

The 1960s were the time of civil rights, the 1970s emphasized women's rights. and the 1980s will embrance the rights of the aging. By then, the median age of the U.S. population will be over 30 and the fastest growing segment of the population will be the 24 or 44 year olds, who underpin the nation's economic growth. With fewer children and more working wives, contact lenses are affordable and attractive but these people are becoming presbyopic. Optometrists interested in contact lenses have liked to think of their patients as youthful so the graying of America will bring sweeping changes to the field. Mature patients deserve the improved vision and pleasure they can experience wearing contact lenses.