Description

The 90D lens is an essential tool in the field of ophthalmology, renowned for its precision and versatility in retinal examination. Manufactured by leading companies such as Volk Optical, this lens is a high-power, double aspheric, non-contact auxiliary lens designed for use with a slit lamp biomicroscope. Its primary function is to provide detailed imaging of the retina, making it invaluable for examining the posterior pole, optic disc, macula, and peripheral retina.

Key Features

• Aspheric Design: The double aspheric design minimizes peripheral image distortion and enhances depth of field, offering clear and comprehensive retinal views.
• Magnification: Provides an image magnification of 0.76x and a laser spot magnification of 1.32x, suitable for both examination and laser procedures.
• Field of View: Offers a static field of view of 74° and a dynamic field of view of 89° when tilted, allowing extensive retinal coverage.
• Working Distance: A 7 mm working distance ensures ease of use and comfort during examination.

Image Characteristics

The lens produces a real, inverted, and reversed image, with the retinal image minified. Further magnification can be achieved using the slit lamp, providing flexibility in examination.

Design and Material

• Compact Size: With a ring diameter of approximately 30 mm, the lens is easy to manipulate within the orbit.
• Optical Glass: Constructed from high-quality optical glass, it boasts a transmittance typically greater than 95%.
• Color Options: Available in various colors including Black, Blue, Gold, Green, Purple, Red, and Silver, with special editions like Champagne Gold.

Practical Applications

The 90D lens is suitable for use with small or undilated pupils and is compatible with most standard slit lamp biomicroscopes. Its portability and user-friendly nature make it ideal for clinical settings, teaching, and research environments.

Maintenance and Care

Cleaning is straightforward, as the lens can be cleaned with alcohol wipes according to manufacturer guidelines. It is advisable to store the lens in a protective case when not in use to prevent damage.

Certifications

Certifications such as CE, FDA, ISO13485, RoHS, and ISO9001 may vary by manufacturer, ensuring adherence to quality and safety standards.

Common Use Environments

Widely used in ophthalmology clinics, hospitals, teaching institutions, and research laboratories, the 90D lens remains a standard tool in ophthalmic practice, often used alongside other diopter lenses like the 20D and 78D. Its comprehensive features and reliable performance continue to uphold its reputation as the gold standard in slit-lamp fundus evaluation.