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Welcome to question of the day #344

Eyetool question of the day #344

I see a lot of older patients and many of them have cataracts and/or age-related macular degeneration causing them problems with near-vision activities such as reading. Some of them may benefit from high near adds such as +4.00 and higher but when I have tried a high add many patients reject them because of the reduced working distance. What can I do?

In my experience, many optometrists are very reluctant to prescribe a near add above +3.00. They fear that the reduced working distance will cause the patient to reject the lenses and this will lead to more chair time and more expense.

Let me take a look at what a +4.00 near add actually does. It has an optimum focal length of 25 cm (almost 10 inches) and when incorporated into the optimum distance refractive correction it will allow the patient to hold something at 25 cm and produce optimum focus. Notice I don’t say optimum clarity.

When a person has cataracts and/or age-related macular degeneration near tasks such as reading are difficult because of blurred/misty and/or distorted vision. This blurred/misty vision is not the same as that caused by an uncorrected refractive error. It is blurred/misty vision caused by cataracts.

Holding something closer to the eyes makes it bigger (proximal magnification) and when something is bigger it is sometimes easier to see.

Holding print at 25 cm makes it bigger and a +4.00 near add allows that print to be as clear as the eye diseases allow. It is easier to read large blurred/misty and/or distorted words than it is to read small blurred/misty and/or distorted vision.

This is how I explain high adds to patients.

‘You need stronger lenses to read better than you are now. You need stronger lenses so you can hold things closer and make them bigger so you can see them better. The lenses will make things a bit clearer but making things bigger will allow you to read smaller print. For the lenses to work you need to hold things at this distance (demo distance to the patient) and you will need to use a reading lamp.

Are you okay to hold things at this distance when reading? If not I won’t recommend these lenses. If you are then I can make some new reading glasses for you to help with your reading.’

I hold the print at the correct focal distance for the lenses and then move the print away to demonstrate more difficult reading if the print is held too far away.

If the patient answers that they are willing to accept the reduced working distance I make a note of this in the clinical records. If the patient answers no then I won’t make up the lenses and consider magnifiers either through my practice or by referral to another.

By taking this time to demonstrate the reduced working distance, asking patients to take part in the decision-making, and advising good light for reading I get very few rejections of high adds.