# Wide Dynamic Range Digital Aberration Measurement and Fast Anterior-Segment OCT Imaging

## TL;DR

This paper introduces a new system that measures eye aberrations over a wide range and provides fast imaging of the eye's front part.

## Contribution

The novel contribution is a dual-modality OCT system with extended defocus range and high-speed imaging capabilities.

## Key findings

- The system achieves a 20 D defocus dynamic range in aberration measurement.
- It provides anterior segment imaging at an A-scan rate of 1.6 MHz.
- Badal-like precompensation extends the dynamic range of digital wavefront aberrometry.

## Abstract

Ocular aberrometry with a wide dynamic range for assessing vision performance and anterior segment imaging that provides anatomical details of the eye are both essential for vision research and clinical applications. Defocus error is a major limitation of digital wavefront aberrometry (DWA), as the blurring of the detected point spread function (PSF) significantly reduces the signal-to-noise ratio (SNR) beyond the ±3 D range. With the aid of Badal-like precompensation of defocus, the dynamic defocus range of the captured aberrated PSFs can be effectively extended. We demonstrate a dual-modality MHz VCSEL-based swept-source OCT (SS-OCT) system with easy switching between DWA and OCT imaging modes. The system is capable of measuring aberrations with defocus dynamic range of 20 D as well as providing fast anatomical imaging of the anterior segment at an A-scan rate of 1.6 MHz.