Original scientific paper
Individually Designed PALs vs. Power Optimized PALs Adaptation Comparison
Nataša Vujko Muždalo
; 1 Master study: Vision Science and Business (Optometry), Aalen, Germany, 2 University of Applied Sciences, Velika Gorica, Croatia, 3 »RA-VU« Optics and Optometry, Rijeka, Croatia 4 »
Matjaž Mihelčić
; University of Applied Sciences, Velika Gorica, Croatia and »Mesec« Optics and Optometry, Jesenice, Slovenia
Abstract
The practice shows that in everyday life we encounter ever-growing demand for better visual acuity at all viewing
distances. The presbyopic population needs correction to far, near and intermediate distance with different dioptric powers.
PAL lenses seem to be a comfortable solution. The object of the present study is the analysis of the factors determining
adaptation to progressive addition lenses (PAL) of the fi rst-time users. Only novice test persons were chosen in order to
avoid the bias of previously worn particular lens design. For optimal results with this type of lens, several individual
parameters must be considered: correct refraction, precise ocular and facial measures, and proper mounting of lenses into
the frame. Nevertheless, fi rst time wearers encounter various diffi culties in the process of adapting to this type of glasses
and adaptation time differs greatly between individual users. The question that arises is how much the individual parameters
really affect the ease of adaptation and comfort when wearing progressive glasses. To clarify this, in the present
study, the individual PAL lenses- Rodenstock’s Impression FreeSign (with inclusion of all parameters related to the user’s
eye and spectacle frame: prescription, pupillary distance, fi tting height, back vertex distance, pantoscopic angle and
curvature of the frame) were compared to power optimized PAL – Rodenstock’s Multigressiv MyView (respecting only
prescription power and pupillary distance). Adaptation process was monitored over a period of four weeks. The collected
results represent scores of user’s subjective impressions, where the users themselves rated their adaptation to new progressive
glasses and the degree of subjective visual impression. The results show that adaptation time to fully individually fi t
PAL is easier and quickly. The information obtained from users is valuable in everyday optometry practice because along
with the manufacturer’s specifi cations, the user’s experience can give us a better insight in design and characteristics of
progressive lenses.
Keywords
progressive lenses; individual parameters; individual progressive lenses; geometry; adaptation time
Hrčak ID:
147688
URI
Publication date:
30.3.2015.
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