The Vision Drum (Dori) is used by optometrists to check the power of the eye. LENSit Dori Vision Drum is very compact, small in size, and requires power to operate. It’s lightweight and easy to hang on the wall. LENSit provides a Manual (Dori) Vision Drum which is manufactured with precision and is designed for your convenience of use. This is the best Dori Vision Drum in India, and we manufacture it according to Indian standards.