Fig. 1
From: Machine learning applied to retinal image processing for glaucoma detection: review and perspective
![Fig. 1](http://media.springernature.com/full/springer-static/image/art%3A10.1186%2Fs12938-020-00767-2/MediaObjects/12938_2020_767_Fig1_HTML.png)
Optic nerve with normal cup and increased cup caused by glaucoma: a, b optic nerve with normal cup and dimension quotes; c, d optic nerve with increased cup