Power of Intraocular lens is determined by?
The most common method of determining IOL power uses a regression formula called 'SRK (Sanders, Retzlaff and Kraff) formula'. The formula is P = A - 2.5L - 0.9K, where: P is the power of IOL,  A is a constant which is specific for each lens type.  L is the axial length of the eyeball in mm, which is determined by A-scan ultrasonography.  K is average corneal curvature, which is determined by keratometry.
Keratometry
Retinoscopy
Ophthalmoscopy
Gonioscopy\/Biometry
Lens