Q. I need to fill a new glasses prescription and my doctor says I need bifocals. I have had discomfort wearing new glasses in the past and I have heard that bifocals are worse. How long should it take to get used to them?
A. Adaptation to a new prescription or even the same prescription in a different set of frames requires visuomotor adaptation. Information from the visual system has to be compared with information from the motor system. The time needed for perceptual adaptation and the remapping of visuomotor space can vary from individual to individual.
Studies showed that the adaptation process is dependent on the number of interactions between the visual and motor system and not on the time spent wearing the prescription.
What all this technical terminology means is that distortions/nausea/dizziness/blurry vision is expected when picking up a new pair of glasses. Some people adapt quicker than others and this depends on how much of a change in prescription there was, the change in the frame shape and/or size, and how adaptable an individual is.
People that change their prescription eyewear every year, and those that have multiple pairs of glasses, have less adaptation issues than those people that wear the same pair of glasses for 10 years. The reason for this is that the person is keeping up with smaller prescription changes and is able to switch between different types of frame styles which allows their brain to re-map the visuomotor dynamics much faster. The longer between prescription changes, the larger the disparity between the old glasses and the new ones, and therefore more difficult to adapt to.
Walking and wearing a new prescription allows for faster visuomotor integration and this explains why sitting down watching TV (no movement) does not allow for proper adaptation. Switching back to the “old” glasses is also not advisable during the adaptation period as this prolongs getting used to the new glasses.
Certain personality types are more adaptable to change than others. Some people can adapt to large changes in 2 days and others need 3 months. Generally the patients with positive attitudes and those determined to make the change in prescription work (for example, those adjusting to invisible bifocals) do much better than the patients that are afraid to try or those that don’t want glasses to begin with. Patients with a history of motion sickness or fear of heights will also have a more difficult time adapting.
The length of the adaptation period really varies from person to person. As long as there is improvement from day to day…then the adaptation is working. I would say a minimum of 2-4 weeks is necessary for most people (especially those adapting to bifocals for the first time). However, with the proper support from the eyecare professional and encouraging people around you…adapting to your new prescription will be successful!
Dr. Patricia Fink
Millcroft Shopping Centre
2080 Appleby Line, Unit E6
Burlington, Ontario, L7L6M6
Tel: (905) 319-1066