The disclosed embodiments include devices, systems, and methods for providing low-cost devices that can measure refractive errors very accurately by attaching to a smartphone. The disclosed device simulates the ambient light or light source in the process of optometrists using the cross cylinder by using the reverse Shack-Hartman technology. The optical device includes an array of small lenses and small pinholes, which will allow the user to effectively focus at different depths. Using an optical device combined with a smartphone, the user first changes the angle of the axis until they see a cross pattern (vertical and horizontal lines are equally spaced apart). The user usually uses the controls on the smart phone to adjust the display so that the lines merge and overlap, which is equivalent to making the view a clear focus, so as to determine the appropriate optical prescription for the user.公開的實施例包括用於提供低成本的設備、系統和方法，該設備可以通過附接到智慧手機非常精確地測量屈光不正。所公開的設備通過利用逆Shack-Hartman技術模擬視光師使用十字柱鏡過程中的環境光或光源。光學裝置包括小透鏡和小針孔的陣列，其將使用戶有效地聚焦在不同深度。使用光學設備並結合智慧手機，用戶首先改變軸的角度，直到看到十字圖案（垂直線和水準線等間距隔開）為止。使用者通常使用智慧手機上的控制項來調整顯示，以使線匯合並重疊，這相當於使視圖成為清晰的焦點，從而為使用者確定適當的光學處方。
