5 Key Takeaways

• 1

  Keratometry samples only the central 3 mm of the cornea, while soft lens sagittal depth depends on lens diameter.

• 2

  Commercial soft lenses with the same base curve can differ in sagittal height by up to 264 µm for daily disposables, 418 µm for reusable lenses, and 345 µm for toric lenses.

• 3

  Changing from a spherical to a toric lens of the same type and manufacturer may alter sagittal height by as much as 500 µm.

• 4

  In 30 subjects, a lens sagittal height 120 to 280 µm deeper than ocular sagittal height was associated with satisfactory fit in a study of 8 daily disposable lenses.

• 5

  In a study of 25 patients with contact lens-related corneal infiltrative events or microbial keratitis, ocular sagittal heights were flatter than the population mean.