A new study published in the the journal Optometry & Vision Science shows that most ready-made reading glasses - the kind you see in bookstores and drug stores are junk. They fail tests to see if they lived up to international optical standards.
The study's authors set out to determine determine whether the optical quality of near-vision (which is the type of vision used when reading) of ready-made spectacles reaches the quality assurance levels required by a published international standard.
The researchers examined a total of 322 randomly selected near-vision ready-made reading glasses of powers +2.50, +3.00, and +3.50 taken from stores in North East England.
Assessments of the optical quality of the glasses were made, and the results were compared against the industry standard and also the more lenient standards used to assess reading glasses in low-resource countries.
Forty-eight percent of the 322 near-vision ready-made reading glasses failed to provide the optical quality required by international standards, with 62% of the +3.50 spectacles failing the requirements. This was principally due to a high prevalence of induced horizontal (60%) and vertical prism (32%) beyond the tolerance levels stipulated industry standard. The figures were similar when the more lenient standards used to assess ready-made reading glasses in low-resource countries were used.
From the study results, we can conclude that for eyeglasses that are up to optical standards, a custom made pair is best and ready-made reading glasses are probably not worth the money spent on them. Glasses that don't measure up to optical standards are undesirable because they tend to cause discomfort like visual fatigue, eye strain, headaches and many other problems. They are also unlikely to fit properly, which can be both annoying and painful.
In a related study, it was found that most the of the glasses sold online are also junk! It seems that newer methods of dispensing eye-glasses such as "ready-made" or "online" have serious flaws and quality issues. The best way to get glasses is actually the traditional way. The reason is that numerous unique and personal factors, from visual behaviour patterns, pupil and eye positions, eye anatomy, the style of the frame, the type of lens and its material all interact in a complex way to determine whether the glasses will work for you. It is just not possible account for this complexity in "ready made" or "online" products.