RAY TRACING BIOMETRICS

When a cataract is operated on, it is usually replaced by an intraocular lens. In order to choose the most suitable lens power, a series of measurements of the eye are taken before surgery to calculate the power of the lens. Once these measurements have been taken (axial length of the eye, refractive power of the lens, depth of the anterior chamber, etc.), formulas are applied to indicate which lens is the most appropriate for implantation.

Instead of applying these formulas, ray-tracing consists of using software to calculate the refraction of the rays on each surface by applying Snell's law. It is especially useful in eyes that have previously undergone refractive surgery and in very short or very long eyes, where the range of error is smaller.