Regular seminar for all employees of IITP will be held on March 21st at 14 o'clock in the conference room on the 6th floor (Bolshoy Karetny per. 19, bld. 1).
The problem of choosing the optimal optotypes for visual acuity assessment: clinical and theoretical aspects.
Speakers: Lebedev D., Rozhkova G., Belozerov A.
Seminar abstract
Visual acuity is one of the main indexes of the visual system condition that is regularly assessed in all the people to reveal any visual disorders or to test a professional suitability, as well as to follow a treatment course in the case of ophthalmic pathology.To ensure the effective diagnostics and reliable monitoring, the measuring procedures have to provide a sufficient accuracy of results. As a rule, visual acuity is determined by finding the smallest size of the special test images – optotypes – that can be detected orrecognized successfully by the subject examined. The optotypes of different sizes can be presented as printed on charts, projected onto a screen, or generated on display. In this talk, we are going to discuss existing variety of optotypes, their evolution since the middle of the XIXth century until the present, advantages and disadvantages of the optotype recommended as a contemporary international standard, and the difficulties of choosing an optimal optotype. The task of optimizing one of the simplest optotypes – the 3-bar target used to assess visual acuity of American military pilots – will be considered in more details. The suggested solution is based on the modeling stimulus recognition process by an average observer. The results of measuring visual acuity with standard and modified optotypes are compared with the results of modeling.
| 15.03.2011 | |