Name of the Procedure:

Press-on Lens, Fresnell Prism, Per Lens
Common Name: Press-on Prism
Technical Terms: Fresnell Prism, Press-on Fresnell Lens

Summary

A Press-on Lens, specifically a Fresnell Prism, is a thin, flexible plastic sheet that is applied to the surface of an existing eyeglass lens. It is designed to correct visual impairments related to eye alignment and binocular vision by altering the direction of light entering the eye. This non-invasive procedure is often used to treat conditions such as diplopia (double vision).

Purpose

The primary purpose of using a Press-on Fresnell Prism is to manage and correct visual symptoms associated with binocular vision disorders. These include:

• Diplopia (double vision)
• Strabismus (misalignment of the eyes)
• Convergence insufficiency
• Other eye alignment issues

The goal is to improve visual clarity and comfort, allowing for better visual function and quality of life.

Indications

A Press-on Fresnell Prism is indicated for patients experiencing:

• Persistent double vision
• Eye strain or discomfort due to misalignment
• Difficulty in performing tasks requiring binocular vision, such as reading or driving

Patients should be evaluated by an eye care professional to determine the appropriateness of this treatment.

Preparation

There is minimal preparation required for this procedure. The patient may need:

• A comprehensive eye examination to assess the degree of misalignment and prism power required
• Possible adjustments in existing vision correction prescriptions if necessary

Procedure Description

1. Assessment: An eye care professional measures the degree of prism needed.
2. Cutting the Prism: The Fresnell Prism sheet is cut to fit the shape of the patient's eyeglass lens.
3. Application: The prism is applied to the back surface of the eyeglass lens, adhering without the need for additional adhesives.
4. Adjustment: The eye care professional ensures the prism is correctly positioned to align the visual fields.

Tools and Equipment: Cutting tools, Fresnell Prism sheet, measuring instruments.

Anesthesia or Sedation: Not applicable, as this is a non-invasive procedure.

Duration

The fitting and application process typically takes about 30 minutes.

Setting

This procedure is usually performed in an outpatient setting, such as an optometry clinic or ophthalmologist's office.

Personnel

• Optometrist or Ophthalmologist
• Trained optical technician (optional)

Risks and Complications

• Common Risks: Temporary discomfort, minor visual distortions as the patient adapts.
• Rare Risks: Potential for incorrect prism strength leading to inadequate correction.

Most complications can be managed with minor adjustments to the prism.

Benefits

Patients can generally expect:

• Improved alignment of the visual fields
• Reduction or elimination of double vision
• Enhanced comfort during visual activities

Benefits can be realized almost immediately after application, although some patients may take a few days to fully adapt.

Recovery

• No significant recovery time required.
• Patients should follow normal eye care routines and attend follow-up appointments for adjustments if needed.
• Monitoring for any discomfort or issues with vision is advised.

Alternatives

• Custom-made prism glasses
• Vision therapy exercises
• Surgical interventions for more severe cases
• Pros of Alternatives: More permanent solutions, especially for surgical interventions.
• Cons of Alternatives: Increased cost, recovery time, and potential surgical risks.

Patient Experience

During the procedure, the patient will experience a fitting and application process that is non-invasive and pain-free. Post-procedure, there may be a brief adjustment period as the eyes adapt to the new visual alignment. Comfort measures include reassurance from the eye care professional and minor adjustments to the prism if necessary. Most patients find significant relief and improved vision shortly after the application.