The 78d Indirect Slit Lamp Lens is intended for general diagnosis and laser treatment, featuring patented double aspheric glass optics that provide excellent imaging of the fundus with balanced magnification to view the optic disc and macula. This is an ideal lens for doctors who regularly cater to populations prone to glaucoma and other posterior pole abnormalities. The double aspheric design and field of view offered by a 78d offers clear and large views of the central mid-retinal regions. This lens offers a high magnification without cutting down too drastically on the field of view. This lens is a popular choice as a general diagnosis lens among doctors who prefer a larger ring size than the more common and smaller profile of the 90d. Dilation is required to obtain optimum retinal imaging with the 78d. The 78d slit lamp lens is available throughout the year in 7 standard colors. Special limited-edition pink lenses are announced periodically on our social media platforms . 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.