The Ohlson VSEF (Vital Stain Enhancement Filters) is a yellow and red filter side-by-side, that easily fits in your pocket. Use the yellow filter for fluorescein examination of contact lens fit. The red filter is used for red lens test and lissamine green examination for dry eye patients.
The filters come in a case to prevent scratching. The case measures 2.25 x 2.6 x 0.535 inches.