Swept-source optical coherence tomography (SS-OCT) image demonstrates some of the many abnormalities that can be present in a highly myopic eye. The magnitude and thickness of the reflection from the ellipsoid layer (arrowheads) shows a rough correlation to the thickness of the underlying choroid, but do vary with the location in the image because of a number of factors, including defocus of the illumination beam and astigmatism. The subfoveal choroid is 15 μm thick and the subfoveal sclera is 78 μm thick. Both measurements are less than 10% of their expected values. The layers of this eye are so thin that it is possible to image structures in the orbit behind the eye, including blood vessels. Note the unusual shape of the eye, which is due to the presence of a staphyloma.