This is the Labeled Optical Coherence Tomography (OCT) and Chest X-Ray Images for Classification dataset, consisting of 3000 images of 2 classes. Each image is a 224x224 single channel (grayscale) image.
Kermany, Daniel; Zhang, Kang; Goldbaum, Michael (2018)
Labeled Optical Coherence Tomography (OCT) and Chest X-Ray Images for Classification, Mendeley Data, v2 http://dx.doi.org/10.17632/rscbjbr9sj.2
The dataset (including source code, images and annotations) is available to download under the Creative Commons Attribution International (CC-BY 4.0). Note that the license includes a disclaimer of warranties and limitation of liability.