Table 1.

Grades of the lens nuclear hardness with the Emery-Little classification strategy in phacoemulsification and feature representation (color information) of the tissue image.

Classification	Medicine name	Lens nuclear color	Label
Normal tissue	—	—	0
Grade I	Very soft nuclear	Transparent and nonnuclear	1
Grade II	Soft nuclear	Yellow or yellow-white	2
Grade III	Medium hard nuclear	Dark yellow	3
Grade IV	Hard nuclear	Brown or amber	4
Grade V	Extremely hard nuclear	Dark brown or black	5