PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “PRESBYOPIA”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

926 records · Page 52Linked to original sources
PubMed1997

Prescribing for the moderate-to-advanced ametropic presbyopic VDT user. A comparison of the Technica Progressive and Datalite CRT trifocal.

BACKGROUND: Use of video display terminals (VDTs) is expected to dramatically increase. This clinical study was performed to examine the moderate-to-advanced ametropic presbyopic VDT user to determine the most prevalent visual or physical symptoms incurred while working at a VDT, and to develop a comparative benefit analysis of two currently available occupational lens designs. METHODS: Twenty-four symptomatic VDT users who were currently wearing a non-occupational lens design were selected from a pool of 100 applicants. The non-occupational lens distribution included 17 bifocals, 3 trifocals and 4 progressives lenses. The subjects compared two occupational lens designs. RESULTS: Statistical analyses indicated that the frequency and severity of seven of 10 symptoms reported were significantly reduced by wearing the occupational lenses, including the three most frequently reported pre-existing symptoms of neck/shoulder aches, eyestrain, and blurred intermediate vision. CONCLUSION: Study results suggest that symptomatic moderate-to-advanced ametropic presbyopic VDT users may benefit from an occupational progressive lens when work involves prolonged or exclusive viewing of a VDT screen. An occupational trifocal may benefit VDT users also required to perform other viewing tasks.

Aged↗
PubMed1997

OPTX 20/20 and Press-On Optics bifocal segments: an evaluation.

BACKGROUND: OPTX 20/20 and Press-On Optics removable bifocal segments were evaluated in three areas: optical quality, effects on vision, and stability under simulated environmental conditions. METHODS: To evaluate optical quality, sphere, cylinder, and spherical equivalent powers were measured in center and peripheral portions of 10 segments, with powers ranging from +1.00 to +2.50 D. RESULTS: Twelve of 20 OPTX 20/20 segments and six of 20 Press-On Optics +1.00 and +1.50 D segments failed to pass ANSI Z80.1 standards because of unwanted cylinder powers. With regard to vision, +2.00 D OPTX 20/20 segments provided a 1 Snellen line advantage in near acuity, as compared with the Press-On Optics segments. contrast sensitivity for low- and mid-spatial frequencies was not significantly different for segments of the two types. CONCLUSION: For higher powers, the optical characteristics of the OPTX 20/20 segments are better and provide better visual acuity. For lower powers, distortion and small amounts of unwanted cylinder reduce the optical quality of the OPTX 20/20 segments. Both segment types retained adhesion to CR-39 carriers equally well and should be satisfactory for their designated purposes of providing temporary and removable adds for occasional use.

Adult↗
PubMed1998

Recent trends in progressive power lenses.

Despite having been first marketed in the 1950s, new designs of progressive addition spectacle lens continue to appear. Some of the recent patent literature is reviewed on the design of such lenses. As well as a number of improvements to general purpose designs, specifically to include aspheric surfaces for the distance portion of progressive lenses, the literature includes a recent patent on an improved version of the Alvarez lateral translation lens system. The optimisation of single vision lens forms in order to extend the depth of field for early presbyopes is also discussed.

Aged↗
PubMed1998

[Scale for evaluating desirable ametropia or eumetropia].

GOAL: The purpose of this study is to assess the degree of desirable ametropia in cataract surgery. MATERIAL AND METHODS: A scale for evaluation was created. It allows to measure the desired distance for a neat uncorrected vision (desired ametropia) after cataract surgery that presbyopic patients (monocular vision) would like to obtain. This scale helps to calculate the power of the intraocular lens to be implanted. The scale was shown to a series of 50 consecutive presbyopic patients. Refraction was the same in both eyes. The interest of patients in the evaluation of their desirable ametropia was measured on a scale from 0 to 5. RESULTS: Interest was good for 50% of patients (grade > or = 3). Mean distance desired by patients for a neat uncorrected vision was 1 meter. Preoperative myopia and hyperopia have no significantive influence upon the distance desired for a neat uncorrected vision. CONCLUSION: The choice of the power of the lens implanted during cataract surgery should take into account the patients' desires. An evaluation of the postoperative desirable ametropia should be systematic.

Activities of Daily Living↗
PubMed1998

The burgeoning presbyopic population: an emerging 20th century phenomenon.

Improved social welfare in the wake of the 'industrial revolution' set in train in mid-18th century Britain an escalation in population numbers which has been sustained through to the end of the 20th century--and is projected to continue into the 21st century. However, within the total population envelope the percentage-contribution of certain age groupings shows a striking pattern when viewed across nearly five centuries. For 350 years, up to the end of the 19th century, the over--40 year old section of the population comprised a steady 25% of the total population count of England (latterly England and Wales): over the same period the 60-plus section contributed nearly 10% of the total. Throughout the ten decades of the 20th century these proportions have both increased, such that with the arrival of the next millennium a two-fold increase in the percentage-contribution of both age groups will have occurred: nearly one-half (over 24 million) of the population of England and Wales will be aged over 40, or more than one-fifth (around 11 million) will be aged over 60 years. This 'ageing' of the general population will have economic and socio-medical implications both at home and abroad, since this is a demographic trend which is present/projected in all countries of the European Union (as presently constituted). The future practise of optometry will certainly be touched by these changes. Naturally a potential increase in demand for presbyopic refractive corrections from the growing volume of aged 40-plus individuals is possible. However of greater significance is the certain increase in age-related oculo-visual problems arising from within the growing aged 60-plus population. Greater acknowledgement and utilisation of the optometrist's skills, currently being reappraised through the profession's participation in 'collaborative care' schemes, may indicate the direction in which optometry should move in the early 21st century to remain a valuable--and valued--health care profession.

Age Distribution↗