1Assistant Professor in Ophthalmology, Shri Sathya Sai Medical College & Research Institute
2Associate Professor in Forensic Medicine & Toxicology, Shri Sathya Sai Medical College & Research Institute
3Professor & Head in, Department of Ophthalmology, Shri Sathya Sai Medical College & Research Institute
*Corresponding Author: Email: kautilya.dactroo@gmail.com
Online published on 5 January, 2016.
Signature is a visuo-motor skill which requires continuous processing of the visual perceptions to execute effectively the fine hand movements. Any defect in the visual inputs could affect a change in the signature. Understanding the variation in signature characters caused by visual acuity change can help better evaluate questioned documents. In our study we try to analyze and catalogue these changes in the signature of a person.
The study was conducted among 100 subjects above 18 yrs of age and having normal visual acuity. They were asked to provide three samples of their signature, after which the same tasks was repeated with serial increments of myopia. Changes in the signature class characters were analyzed and compared in all grades of myopia.
In this study it was found that there was increase in signature size, signature space between letters and decrease in the Middle zone letter size in different grades of induced myopia. The signature slope and letter slant also changes in most subjects with change in the visual acuity. The changes were not linear and coudn't be used to predict the grade of myopia.
From the findings of the study it could be concluded that visual processes significantly influence the signature and myopia by effecting the visual acuity would induce corresponding changes in the signature class characters. These changes need to be kept in mind while evaluating question documents.
visual acuity, class characters, myopia, Signature
