With a wide field of view, this lens offers visualization past the mid peripheral region up to the equator and the peripheral retina upon dynamic examination. The optical design and power of this lens makes it a great choice when working with patients that have a small pupil or do not respond well to dilation such as infants or older populations. The small profile as well as a closer working distance make enable the doctor to easily manipulate the lens for a quick examination, especially with patients who may not remain still for a long time. Most widely used for examination and assessment of Retinopathy of Prematurity (ROP) and peripheral retinal defects such as tears and detachments. The 28D BIO lens is available throughout the year in 7 standard colors. Volk Optical warrants its Non-contact Slit Lamp and BIO Lenses against defects in materials or workmanship for a period of 10 years from receipt by end user. This warranty is valid only on lenses purchased directly from Volk Optical Amazon store, Volk.com, or an authorized Volk distributor.