{
  "annotation_id": "11831975-230d-4113-98c0-6e1e43a53c57",
  "date_created": "2026-03-02T18:00:45.965000Z",
  "date_modified": "2026-03-02T18:00:45.965000Z",
  "file_hash": "7581c05efbbde3f4bb9d3681c926ede6c83ab3f0291ebdc25b64ce1fbd29fb8e",
  "private": false,
  "record": {
    "abstract": "Optical sections of the cornea are obtained by illumination with a collimated\nbeam expanded in a fan shape by a small rotary cylindrical lens. The light\ndiffused from the cornea is observed by two cameras and processed in order to\nyield the surfaces\u0027 profiles. The optical system used to project a thin\nrotating line on the cornea consists of a white light source provided with\noptical fiber bundle output which is first conditioned by a set of lenses so\nthat it would produce a spot on the cornea. A small cylinder lens is used to\nexpand the beam in one direction so that a thin line illuminates the cornea,\nrather than a spot. The cylinder lens is provided with motor driven rotation\nabout an axis normal to its own in order to rotate the line on the cornea such\nthat the projected line scans the whole cornea; the illuminator is completed\nwith a slit aperture. The cornea is not perfectly transparent, scattering some\nof the light that traverses it; this fact is used for its observation by two\ncameras. These are placed at pre-defined angles with the illumination axis, so\nthat optical sections of the cornea can be seen; the use of two cameras avoids\nthe need for camera rotation in synchronism with the cylinder. The two cameras\u0027\nimages can be combined in order to simulate a single virtual rotating camera.\nImage processing is used to extract information about the corneal surfaces\nprofiles and thickness from the optical sections. Several peculiar aspects of\nprocessing are discussed, namely the corneal edge detection algorithm, the\ncorrection for angle of view and deformation due to observation of the inner\nsurface through the cornea.",
    "arxiv_id": "physics/0311004",
    "authors": [
      "Jose B. Almeida",
      "Sandra Franco"
    ],
    "categories": [
      "physics.med-ph",
      "physics.optics"
    ],
    "title": "3-Dimensional Mapping of Corneal Topography and Thickness",
    "url": "https://arxiv.org/abs/physics/0311004"
  },
  "schema_id": "dorsal/arxiv",
  "source": {
    "execution_id": "7f769a37-cece-4f30-9cd0-672215b0bfc6",
    "id": "arXiv Dataset IDs",
    "type": "Model",
    "variant": "snapshot-2026-03-01",
    "version": "0.1.0"
  },
  "user_id": 1000002
}