NCJ Number
217659
Journal
Journal of Forensic Sciences Volume: 52 Issue: 2 Dated: March 2007 Pages: 406-411
Date Published
March 2007
Length
6 pages
Annotation
This study presents a Web-based tool that can be used to assist in identifying unknown individuals by using eyewear prescriptions.
Abstract
The study found that the features of prescription eyewear found at a recovery or crime scene could place individuals whose eye condition matched a prescription at the scene while eliminating other individuals. Further, the frequency of a given eyewear prescription indicates the rarity of an individual's eye condition, i.e., the probability of a random individual having the same refraction error by chance alone. This increases the certainty of an accurate identification. Also, the frequency of a refraction error can be combined with other data, such as dental data, to increase the probability of identification accuracy. Three databases totaling just over 385,000 individual eyewear prescriptions were used in this study in order to allow forensic analysts to determine the strength of the individualization of an eyewear prescription match to records by calculating the frequency at which the observed eyewear prescription occurred in various U.S. populations. The paper explains optical refractive errors, which are essentially distortions of light waves as they pass through the eye, causing a blurry or out-of-focus image on the retina. Prescription lenses correct these vision impairments. Refractive errors can be unique to an individual or relatively common in a population. Single-eye refractive errors can be common, rare, or unique. Dual-eye refractive errors are typically rare to unique, particularly in cases of astigmatism. This paper also explains potential states and combinations of refractive errors, and the measurement of corrective lenses is discussed. Detailed descriptions of the databases used are provided. The practical application of this system is demonstrated with two recent forensic identifications that involved missing U.S. service personnel killed during the Vietnam War. 6 figures and 9 references