If a GP lens fails to provide acceptable visual acuity, what should the fitter first do?

When a GP (gas permeable) lens fails to provide acceptable visual acuity, the initial step a fitter should take is to have a sphero-cylindrical over-refraction performed. This process involves the use of a trial lens to assess whether additional spherical or cylindrical power is needed to correct the patient's vision effectively.

Conducting an over-refraction helps determine if the current lens prescription is adequate for the patient's visual needs. It is essential to establish whether the lens is simply uncorrected in power or if there is an issue with the fitting or lens surface before proceeding to any further steps.

Engaging in this assessment provides critical information, which can indicate whether the cause of poor visual acuity lies in the lens's prescription itself or if adjustments in fit or additional evaluations are necessary. After determining the over-refraction results, the fitter can make informed decisions about whether to replace the lens, change the lens material, or assess the lens surface for deposits based on the findings.