It is used to calculate the power of the intraocular lens (IOL: intraocular lens) that will be placed during cataract surgery. There are two types of Biometrics.

A-Ultrasonic (A-scan) Biometry: It is a widely used method. This method is used especially in advanced cataracts.
B-Optical Biometry: Although it is a sensitive method, it is the biggest disadvantage that most of the cataracts in our country cannot be measured. It is preferred in non-advanced cataracts. It is done without touching the patient and in a sitting position.

In the biometry performed with the contact method, the margin of error varies according to the person measuring. Biometry with the immersion method gives very sensitive and accurate results. For this reason, this method should be used especially in patients with multifocal IOL. The biggest disadvantage is the application of drop anesthesia to the patient and performing it in a supine position.