Description

The Fresnel Press-On Prism by 3M is an innovative solution for temporary prismatic correction in ophthalmic care. Crafted from optical-grade polyvinyl chloride (PVC), this thin, flexible, and transparent sheet is designed to adhere seamlessly to the inner surface of spectacle lenses using only water, eliminating the need for adhesives.

Key Features

• Customizable Fit: Easily cut to match any lens shape, allowing for both full-lens and sectorial applications.
• Minimal Bulk: With a thickness of approximately 0.8–1 mm, it adds negligible weight and thickness to spectacles.
• Versatile Prism Power: Available in a wide range of powers from 0.5 to 40 prism diopters, catering to diverse clinical needs.

Intended Use

The prism is primarily used for managing conditions such as diplopia (double vision) associated with strabismus, nerve palsies, nystagmus, and other visual field defects. It serves as a valuable tool in binocular vision therapy, offering a temporary or trial correction that can be easily adjusted or removed as needed.

How It Works

By altering the direction of light entering the eye, the prism shifts images to relieve diplopia, expand the visual field, or assist in vision therapy. It can be applied to one or both lenses at various axes, providing a tailored correction with minimal magnification effects.

Application Instructions

1. Preparation: Clean the spectacle lens and the prism with warm water and mild detergent.
2. Attachment: Submerge both in lukewarm water, align the prism, and press gently to remove air bubbles.
3. Drying: Allow to dry for 24 hours for optimal adhesion.
4. Trimming: Trim the prism to fit the lens shape, avoiding overlap with the lens frame.

Maintenance

Cleaning is straightforward, using warm water, mild detergent, and a soft brush. Avoid alcohol-based cleaners and lens wipes to prevent damage. If the prism detaches, it can be easily reapplied with water.

Advantages

• Ease of Use: Simple application and removal without harming the carrier lens.
• High Prism Powers: Achievable without the bulk of conventional prisms.
• Cost-Effective: Suitable for temporary corrections and diagnostic purposes.

Considerations

Some users may experience a slight reduction in visual acuity, particularly at higher prism powers. Other potential effects include blurring, distortion, and visible grooves that require careful cleaning. Despite these, the prism remains a cosmetically discreet and practical option for many patients.

Safety Precautions

While generally safe, users should exercise caution if using the prism for driving and consult relevant authorities. It is typically employed as a temporary measure until a permanent solution is viable or the underlying condition improves.

The Fresnel Press-On Prism offers a unique blend of flexibility, functionality, and convenience, making it an essential tool in the management of complex visual conditions.