AUTHOR=Zhang Shuhe , Webers Carroll A. B. , Berendschot Tos T. J. M. TITLE=Computational single fundus image restoration techniques: a review JOURNAL=Frontiers in Ophthalmology VOLUME=Volume 4 - 2024 YEAR=2024 URL=https://www.frontiersin.org/journals/ophthalmology/articles/10.3389/fopht.2024.1332197 DOI=10.3389/fopht.2024.1332197 ISSN=2674-0826 ABSTRACT=Fundus cameras are widely used by ophthalmologists for monitoring and diagnosing retinal pathologies. Unfortunately, no optical system is perfect, and the visibility of retinal images can be greatly degraded due to the presence of problematic illumination, intraocular scattering, or blurriness caused by sudden movements. To improve image quality, different retinal image restoration/enhancement techniques have been developed, which play an important role in improving the performance of various clinical and computer-assisted applications. This paper gives a comprehensive review of these restoration/enhancement techniques, discusses their underlying mathematical models, and shows how they may be effectively applied in real-life practice to increase the visual quality of retinal images for potential clinical applications including diagnosis and retinal structure recognition. All three main topics of retinal image restoration/enhancement techniques, i.e., illumination correction, dehazing, and deblurring, are addressed. Finally, some considerations about challenges and the future scope of retinal image restoration/enhancement techniques will be discussed.