A simple and accurate system of cataract classification using slit lamp and direct ophthalmoscope is reported. Lens opacities are classified into cortical (anterior and posterior), nuclear and posterior sub-capsular and each sub-type of opacity is graded, extent and density wise, using both slit lamp and direct ophthalmoscope. A circle representing enface view of opacity divided into 100 equal parts is used in calculating the area of each opacity. This classification takes into account both the area and depth of opacity in arriving at the total extent of sub-type of each opacity. For density determination, we do not recommend the use of a resolution target projection ophthalmoscope. Intra-observer and inter-observer variability studies using this classification system indicated that the classification system is fairly reliable.