Estimate peripheral retinal defocus signal from lens power and ocular geometry.
RPD>0 为近视性离焦,RPD<0 为远视性离焦;结合镜片类型评估近视防控效能。
| 方案 | RPD目标 | 机制 | 效果 |
|---|---|---|---|
| 单光镜片 | 通常<0 | 常致周边远视性离焦 | 无防控,可能加速 |
| 离焦镜片(DIMS) | +1~+3D | 周边正微透镜产生近视性离焦 | 延缓50-60% |
| 角膜塑形镜 | +1~+2D | 重塑周边角膜产生近视性离焦 | 延缓40-60% |
| 多点离焦(HALT) | +1~+3D | 11圈微透镜阵列持续离焦 | 延缓60%+ |
| Item | Formula / Note | Source / Standard |
|---|---|---|
| Defocus | Defocus = peripheral refractive error minus the correction required there, in dioptres | ISO 13666:2019, Ophthalmic optics - Vocabulary |
| Relative peripheral refraction | Measured relative to the central prescription, giving positive or negative peripheral defocus | ISO 13666:2019, Ophthalmic optics - Vocabulary |
| Sign convention | Positive indicates hyperopic defocus (image behind the retina); negative, myopic defocus | ISO 13666:2019, Ophthalmic optics - Vocabulary |
| Role of lens design | Progressive and defocus-control designs reshape the peripheral power profile | ISO 8980-2:2017, Uncut finished spectacle lenses - Part 2: Progressive power lenses |
计算相对周边离焦量(RPD),评估近视防控镜片的离焦信号强度与方向。
周边离焦信号量计算器,计算相对周边离焦量(RPD),评估近视防控离焦信号。。医疗专业工具,基于权威医学标准,仅供参考。