{"id":640623,"date":"2024-11-06T01:17:29","date_gmt":"2024-11-06T01:17:29","guid":{"rendered":"https:\/\/pdfstandards.shop\/product\/uncategorized\/iso-tr-289802007\/"},"modified":"2024-11-06T01:17:29","modified_gmt":"2024-11-06T01:17:29","slug":"iso-tr-289802007","status":"publish","type":"product","link":"https:\/\/pdfstandards.shop\/product\/publishers\/iso\/iso-tr-289802007\/","title":{"rendered":"ISO\/TR 28980:2007"},"content":{"rendered":"

The purpose of ISO\/TR 28980:2007 is to explain the changes relating to power measurements in the revised editions of ISO 8980-1 and ISO 8980-2.<\/p>\n

In order to illustrate the issues raised, an inter-laboratory power measurement study was conducted on ten different lenses measured by nine organizations worldwide. Twenty-five focimeters of different types were used. The test lenses were spherically powered allyl diglycol carbonate (ADC) hard resin lenses surfaced to -4,00 D, -2,00 D, 0,00 D, +2,00 D, and +4,00 D, each with an addition power of 2,50 D. Five were D28 bifocals and five were progressive power lenses. The measurements were front distance power, front near power, back distance power and back near power, for each lens and for each focimeter used. Each lens was measured nine times: five measurements taken without repositioning the lens and four measurements taken with the lens repositioned each time.<\/p>\n

The assessed parameters were divided in three categories:<\/p>\n