Simple CCTV for Severe and Profound Low Vision

Patients Taweekit Nimvorapun, M.D.
Apatsa Lekskul, M.D.
Kitikul Leelawongs, M.D.
Rungroj Lerdvitayasakul, M.D.
*Department of Ophthalmology, Faculty of Medicine Ramathibodi Hospital

ABSTRACT :

Objective : To make a simple low cost closed-circuit television (Simple CCTV) for the severe and profound visual impairment patients

Methods : We used to bottle (1.5 L) of water to make a handheld and mounted the video camera in the handheld. The handheld video camera can project a magnified image onto a television screen. The handheld cameras are portable systems designed for viewing the characters of newspapers (equivalent to J5 or 20/50 of Lea number at 16 inches). Three sizes of simple CCTV #1, #2, #3 were made. These CCTV’s connected to TV 5.5”, 14”, 21”, 29”, respectively. Fluorescent lamp was used as a light source.

Result : Simple CCTV #1 can electronically magnify up to 3.4 x, 10x, 13x, 18x and displays 17 to 21 characters on the televisions. Number 2 can magnify up to 7x, 21x, 30x, 40x, and 8-10 characters, and number 3 magnifying up to 13x, 40x, 50x, 70x and 4-5 characters.

Conclusion : Simple CCTV can magnify the characters of newspaper as good as standard CCTV, but simple to be made, much less expensive.

Thai J Ophthalmol 2003 ; July – December 17(2) : 115-124.