Provide a valuable resource to your clients or customers by linking to this resource page. Just place the following link on your website.
A waxy disc is a small, handheld testing target used by eye doctors to measure and refine the near vision prescription. It is a round, flat target containing standardized rows of letters or text that decrease in size.
read more about waxy disc in optics ...The primary purpose is to assess near visual acuity and focus accommodation (the eye's ability to focus up close). The patient holds the disc at a set reading distance (usually 14 to 16 inches) and reads the smallest line they can clearly see. This measurement is vital for diagnosing presbyopia and determining the power of reading glasses or bifocal segments. The test relies on isolating near vision sharpness.
The disc often features different scales, such as Snellen acuity (e.g., 20/20, 20/40) and Jaeger Notation (e.g., J1, J2). Jaeger Notation is a traditional scale that uses graded text sizes to measure functional reading ability. Both scales quantify the smallest detail the patient can resolve at near distances.
The doctor uses the disc during the near refraction test. They place different power lenses in front of the patient's eye until the patient can read the smallest line possible on the disc. The needed power is the add power required for comfortable reading.
The near vision measurement is essential for prescribing multifocal contact lenses. The "add power" (the extra power needed for reading) determined by the waxy disc test is directly translated to the near zone power in a multifocal or bifocal contact lens. This ensures the lens provides sufficient magnification for close work.
This measurement is necessary for diagnosing and quantifying presbyopia, the age-related stiffening of the lens. The waxy disc test reveals the degree to which the patient has lost natural focusing ability.
No, the test is painless and involves reading text targets.
No, the disc is used for sharpness (acuity), not color perception.
No, the waxy disc test is done before dilation.
The "Waxy Disc" (Potential Acuity Meter or PAM) is often used before cataract surgery to predict your vision after the cloudy lens is removed. If you have both a cataract and macular disease, this test helps your surgeon determine if surgery is likely to provide a meaningful improvement in your sight.
AAO. Potential Acuity Testing (aao.org). 2024.
Mayo Clinic. Cataract Surgery Preparation (mayoclinic.org). 2024.
ASCRS. Pre-operative Visual Assessment (ascrs.org). 2024.
Review of Optometry. Predicting Post-Op Vision (reviewofoptometry.com). 2024.