I see a lot of patients with cataracts. Sometimes it takes me a long time to get a subjective refraction result and even then I’m not sure I have got the optimum result. What can I do?

The presence of cataracts causes the patient to have blurred, misty, and poor contrast vision. When asking them to compare lenses ‘is it clearer with 1 or 2?’ it can be very difficult for them to see any difference in vision between the two lenses you have presented.

The first thing to do is to realise that it is the cataract that is making it difficult for the patient to notice a difference and making it difficult to make a choice between the lens options.

The second thing to do is to use lenses with a larger difference between them so ask to compare between + and -0.50 rather than + and -0.25 both with the spherical and cylinder choices.

If the patient can give a meaningful choice you may then want to manipulate the final lens choice using your clinical experience.

You also may want to take into account the current prescription and what the visual acuities are with this prescription. If the visual acuity is good the new prescription may be close to the current prescription.

Take your time and be patient.