{
  "patent_number": "US 4665913",
  "country": "US",
  "title": "How Lasers Correct Vision by Reshaping the Eye's Front Surface",
  "original_title": "Method for ophthalmological surgery",
  "summary": "This patent describes a method for precisely reshaping the front surface of the eye using an ultraviolet laser to correct vision problems like nearsightedness, farsightedness, and astigmatism.",
  "what_it_does": "The patent details a method for changing the optical properties of an eye by operating solely on the cornea's anterior surface. It uses selective ultraviolet (UV) laser radiation to remove corneal tissue through a process called ablative photodecomposition (Claim 1). This process sculpts the cornea to a predetermined curvature profile, correcting vision defects. For example, to fix astigmatism, the laser beam is focused to a tiny spot and scanned over the cornea in a specific pattern, removing tissue to a precise depth (Claim 3). This scanning action changes the cornea's shape, allowing it to focus light correctly.",
  "what_it_does_not_cover": [
    "Does not cover vision correction methods that operate on parts of the eye other than the anterior surface of the cornea.",
    "Does not cover laser eye surgery using non-ultraviolet light, as it specifically claims \"ultraviolet irradiation\" (Claim 1).",
    "Does not cover methods that reshape the cornea without removing tissue through \"ablative photodecomposition\" (Claim 1).",
    "Does not cover techniques that do not aim for a \"predetermined curvature profile\" to correct specific vision errors (Claim 1).",
    "Does not cover procedures where the laser ablation does not penetrate into the stroma layer of the cornea (Claim 1)."
  ],
  "filed": "1985-06-24",
  "granted": "1987-05-19",
  "expires": "2005-06-24",
  "status": "expired",
  "holder": "LRI LP",
  "holder_url": "https://patentbrief.org/company/lri-lp",
  "inventors": [
    {
      "name": "Francis A. L'Esperance, Jr.",
      "url": "https://patentbrief.org/inventor/francis-a-lesperance-jr"
    }
  ],
  "times_cited": 381,
  "tags": [
    "medical_devices",
    "biotech",
    "healthcare",
    "lasers",
    "ophthalmology"
  ],
  "abstract": "The invention contemplates use of a scanning laser characterized by ultraviolet radiation to achieve controlled ablative photodecomposition of one or more selected regions of a cornea. Irradiated flux density and exposure time are so controlled as to achieve desired depth of the ablation, which is a local sculpturing step, and the scanning action is coordinated to achieve desired ultimate surface change in the cornea. The scanning may be so controlled as to change the front surface of the cornea from a greater to a lesser spherical curvature, or from a lesser to a greater spherical curvature, thus effecting reduction in a myopic or in a hyperopic condition, without resort to a contact or other corrective auxiliary lens technique, in that the cornea becomes the corrective lens. The scanning may also be so controlled as to reduce astigmatism and to perform the precise incisions of a keratotomy. Still further, the scanning may be so controlled as to excise corneal tissue uniformly over a precisely controlled area of the cornea for precision accommodation of a corneal transplant.",
  "url": "https://patentbrief.org/patent/us/4665913/laser-eye-surgery-lesperance",
  "markdown_url": "https://patentbrief.org/patent/us/4665913/laser-eye-surgery-lesperance/md",
  "google_patents_url": "https://patents.google.com/patent/US4665913",
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}