Presbyopia: When the flexibility of the lens declines typically due to age.
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Hyperopia: When the optics are too weak for the length of the eyeball, one has hyperopia or farsightedness.
Soft error | Forward error correction | Xero Error | Inborn error of metabolism | Error detection and correction | Source-monitoring error | scrivener's error | Round-off error | Refractive surgery | refractive surgery | Postage stamp design error | postage stamp design error | One error and its catastrophic results: ''Napoleon's invasion of Russia#Retreat | Off-by-one error | Observational error | Margin of Error (The Wire episode) | Margin of Error | List of refractive indices | Human error assessment and reduction technique | error function | error detection and correction | Erotic target location error | End of an Error (2004-2006) | End of an Error | Discretization error | Clerical error | Berkson error model |
Ian Berger and Larry Spitzberg at the University of Houston College of Optometry in Houston, Texas, to provide a simple, inexpensive means for measuring refractive error in human vision.