The measurement of the axial length of the eye is indispensable for the determination of the power of intraocular lenses. The generally established method for the determination of intraocular distances is that of ultrasonic biometry. Different methods are used to measure the axial length of the eye. These methods include contact biometry or immersion technique using the A-scan probe (10 MHZ).Recently , non-invasive optical biometry methods were developed, which are based on the principle of partial coherence interferometry (PCI ) .The IOL Master is the first Optical biometry introduced in the market which emits light in the visible & infrared spectral regions. It is a combined biometry instrument, which measures parameters of the human eye needed for intraocular lens calculation. All measurements are non-contact measurements.