Understanding mechanism of progression of short-sightedness using progressive addition lenses

Short-sighted participants will be recruited from Queensland University of Technology and they will be provided with progressive addition lens spectacles to wear during waking hours. Progressive addition lenses contain a corridor of increasing power between distance and near zones, and are used to slow the worsening of myopia in children and young adults. Two designs of the progressive addition lenses will be used. Type 1 is a conventional lens design with a wide corridor and type 2 is an interventional design with a narrow corridor. Participants will be followed up every three months for 12 months to measure the focussing error. The principal investigator (PI), who is an optometrist, will perform refraction to check the power of the spectacles under supervision of A/Prof Katrina Schmid and Prof David Atchison in the Myopia Lab at the Queensland University of Technology. Then, the dispenser at the QUT optometry clinic verifies the segment heights measurements of the PI before ordering the spectacles. The participants will be asked to wear the spectacle during usual waking hours. The prescription of spectacles for distance will be between -1.0 and -6.0 dioptre with the addition power of 1.50 D. The focussing errors of the participants will be measured with the new spectacles at 0, 3, 6, 9 and 12 months timeline from the commencement of the intervention. When the spectacles arrived from the lab, the prescription will be verified and the vision at far and near will be checked. After spectacles are provided, the participants will be contacted via text or phone in a week to check the adaptation with the spectacles and duration of the spectacles wear. The participant will be contacted again after a month to assess the adaptation and duration of wearing hours.