A Comparative Investigation of Prescriptive Ophthalmic Lens Parameters

Mohammad Ghassemi Broumand, Hassan Ghasemi, Saeed Rahmani, Seyed Mehdi Tabatabaeei, Mohammad Reza Nazari, Mohsen akhgary, Pourya Ghasemi Bruomand

Abstract


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Background and Aim: Wearing spectacles is the most common procedure for correction of refractive error and because of its close relationship with eye; the standards of frame & lens of glasses play a very important role in preventing vision problems. The purpose of this study was to compare spherical & cylindrical power and prismatic effect of plastic ophthalmic lenses with Iranian national standards.

Material & Method: In this Cross sectional-Comparative study 48 plastic ophthalmic single vision lenses were inspected & compared with relative national standards i.e.: ISIRI 8715-1:1385.

Results: The spherical power factor with instruments set as step 0.01, all the cases(-1.00,-3.00,-6.00) were in tolerance with limits of the standards (±0.12 D) .The instrument was set for 0.01 step for cylindrical power, at -6.00 D 100% of lenses had no cylindrical power. At -3.00 & -1.00 D about 99% were in tolerance with the standards (±0.09 D).The effect of horizontal & vertical prism, at the power of -6.00 all lenses show prismatic effect but 99% were in tolerance with the standards (±0.85D). At the power of -3.00 & -1.00 D, prismatic effect of lenses were in tolerance with relative standards (±0.55, ±0.35), respectively.

Conclusion: All single vision were collected from famous companies showed the quality of passing all factors of tests & gained Iranian national standards i.e.: ISIRI 8715-1:1385.

Key words: Ophthalmic lenses, Lensometry, Iranian national standards

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DOI: https://doi.org/10.22037/r.m.v1i4.4985

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