Lensometer is mainly used for measuring the optical power and other parameters of eyeglass lenses. By detecting the position of the lens surface, the device is able to determine whether the lens has been ground correctly, and to calculate its ability to bend and refract light.

Lensometer is also used for fitting eyeglasses. The device can measure the lens tilt and tilt direction, and the eyeglass prescription can be adjusted accordingly. This makes it easier for individuals to adapt to their new eyewear.

Lensometers can also be used in the fitting of contact lenses. By measuring the power and curvature of contact lenses, practitioners can determine the right lens for a patient to improve visual acuity.

Lensometer can also be used for quality control of lenses. By measuring the parameters of lenses such as surface power, cylinder axis, and curvature, lens manufacturers can ensure the quality of their products before they are sold.

Lensometers can be used as part of an eye exam to detect possible irregularities in the lens or cornea. The device can be used to detect cataracts or other refractive errors that may require treatment.