CORN1500 is a new corneal nerve dataset which was particularly designed for tortuosity grading tasks. The newly constructed CORN1500 aims to expand the dataset pool for tortuosity grading. Similar to CORN-3, all 1500 CCM in CORN1500 were acquired using a Heidelberg Retina Tomograph equipped with a Rostock Cornea Module (HRT-III) microscope. Each image has a resolution of 384 × 384 pixels covering a field of view of 400 × 400um2. All images were manually annotated by the same ophthalmologist as before into four tortuosity levels (level 1 to level 4) and divided into a training set (1200 images) and testing set (300 images).