The role of bifocals in the management of accommodative esotropia
Jan-Tjeerd de Faber in 28th European Strabismological Association Meeting, 2020
Bifocals should be used in patients who are ortophoric for distance, or have a minimal residual esotropia after full cycloplegic correction, and who still have an esotropia for near, which is converted into esophoria with the help of additional plus lenses. In case of amblyopia, or a residual esotropia, in spite of additional plus lenses, bifocals are contraindicated. The smallest additional plus lens that converts the esotropia for near to an esophoria, should be prescribed. It is, however, noteworthy that the bifocal segment is placed properly and high enough to facilitate the child to use it for near work. Although small bifocal segments and progressive glasses are cosmetically attractive, they do not always achieve this goal. Finally, children with bifocal glasses must repeatedly be refracted in cycloplegia and the near addition should gradually be weaned off.
Computers and the Private Practitioner in Occupational Therapy
Florence S. Cromwell in Private Practice in Occupational Therapy, 2013
Personal experience alerted the author to a potential problem for individuals who wear bifocal corrective lenses. In bifocals, the near vision corrective field is in the lower frame of the eyeglasses. The upper frame is corrected for distance vision. The individual wearing bifocals is subject to experiencing neck discomfort when he attempts to see more clearly by extending the neck to read the screen through the lower frame, or taking the other option, experiencing eyestrain by keeping the head neutrally positioned while viewing the screen through the improperly focused upper frame. Neither solution is comfortable or recommended. To remediate this problem, reading or near vision glasses were purchased for explicit use with the computer. The eyeglasses are stored in the drawer of the computer desk so they are always available. Since use of bifocals is common for the elderly, this is a concern to which the therapist must be alert when instructing the older patient in computer use.
Falls
Charles M Court-Brown, Margaret M McQueen, Marc F Swiontkowski, David Ring, Susan M Friedman, Andrew D Duckworth in Musculoskeletal Trauma in the Elderly, 2016
Aside from a poor level of visual acuity, visual field deficits, impaired depth perception, low contrast sensitivity, stereoacuity and changes in visual acuity demonstrate even stronger links with falls. Surprisingly, the effect of vision improvement through cataract surgery may in fact increase falls rate. This effect on falls rate is similar to that seen in patients with new spectacles. New spectacles may be associated with changes in magnification, optical centres, lens type (e.g. progressive addition lens [PAL] rather than single vision lens) and position of bifocals/PALs, which could adversely affect falls risk. A change from a distance single vision lens to PALs or bifocals distorts the peripheral visual field in PALs and provides a blurred and magnified view of the lower visual field beyond near working distance in both PALs and bifocals. This affects the peripheral optic flow information used for postural control and makes it difficult to judge the position of obstacles in the lower visual field, including obstacles, step and stair edges and/or foot placements relative to such environmental obstacles. Thus the recommendation is that changes to refractive corrections in older people should be conservative, and PALs or bifocals should never be prescribed to patients who are used to wearing single vision glasses and who could be categorized as at high risk for falls.
Optical and pharmacological strategies of myopia control
Published in Clinical and Experimental Optometry, 2018
There are two categories of optical lens designs: concentric ring or bifocal lens design and progressive power or peripheral add lens design. Both designs impact the central and peripheral retinal images (Figure 2). The concentric ring lens design incorporates alternating distance correction and treatment (plus power) zones to provide two focal planes or simultaneous distance correction and retinal myopic defocus. The rationale behind this design is to provide good visual acuity while myopic defocus is simultaneously induced onto the retina during both distance and near viewing.2011 On the other hand, the progressive power lens design incorporates a gradual change in curvature to provide a central zone of distance correction with a progressive change to include a relative plus add in the periphery. This design aims to provide clear central vision while inducing peripheral myopic defocus during both distance and near viewing. Further details of various investigational lens designs reported in the literature are summarised in Table 1.
Diagnosis and Management Practice Patterns among Pediatric Ophthalmology Personnel in Israel
Published in Journal of Binocular Vision and Ocular Motility, 2019
Guy Barnett-Itzhaki, Asaf Friehmann, Zohar Barnett-Itzhaki, Noa Ela-Dalman
Bifocal and multifocal spectacles are the standard of care for reducing the near angle of deviation in patients with ACC ET.25 Most pediatric ophthalmologists and orthoptists use multifocal lenses in the treatment of ACC ET with high accommodative element. Cumulative results show that most pediatric ophthalmologists and orthoptists who use multifocal modality do so up to age 6 years. Most of the pediatric ophthalmologists and orthoptists who prescribe multifocal lenses for ACC ET with high accommodative element provide specific directions in the prescription. Further investigation regarding the use of these lenses and their effects will provide more information about this treatment modality, which is gaining popularity among Israeli pediatric ophthalmology personnel. Our study found a trend toward more orthoptists weaning bifocals gradually for ACC ET with high accommodative element, as compared to pediatric ophthalmologists. Previously published studies on the weaning process were not available for comparison.
Population-based assessment of prevalence of spectacle use and effective spectacle coverage for distance vision in Andhra Pradesh, India – Akividu Visual Impairment Study
Published in Clinical and Experimental Optometry, 2022
Srinivas Marmamula, Saptak Banerjee, Vijay Kumar Yelagondula, Rohit C Khanna, Rajesh Challa, Ratnakar Yellapragada, Jill Keeffe
The prevalence of current spectacle use was 43.1% (95% CI: 41.2–45.0; n = 1,115). Bifocals were the most common type of spectacles (81.8%; n = 912) followed by single vision spectacles for distance (15.9%; n = 177), spectacles with progressive addition lens (1.4%; n = 16) and single vision spectacles for near (0.9%; n = 10). The private eye clinics were the leading spectacle providers (83%; n = 926) followed by eye screening programs/government primary health centres (12.5%; n = 139), optical shops (2.8%; n = 31) and LVPEI centres (1.7%; n = 19). The amount of money paid for procuring the spectacles ranged from Indian Rupees 100 (equivalent to 1.4 USD) to Indian Rupees 6500 (equivalent to 88 USD) with mean of Indian Rupees 823 (equivalent to 11.2 USD).
Related Knowledge Centers
- Astigmatism
- Presbyopia
- Retina
- Glasses
- Near-Sightedness
- Far-Sightedness
- Trifocal Lenses
- Progressive Lens
- Liquid Crystal
- Mosquito