Myopia of adult onset. Can analyses be based on patient memory?

One hundred and fifty-one adult subjects (age 26-64 years) with simple myopia ('simple' = absence of significant astigmatism and anisometropia) were asked about their myopia onset, here defined as the age when first having spectacles to correct vision trouble for distance. A precise memory appeared in 148. Usually, they could substantiate their information by detailed accounts regarding how and when. Evidently, the first pair of glasses is a strong emotional experience. Accordingly, information appears to be reliable when properly asking the patient. The sample confirmed established knowledge: the earlier the onset, the higher the final myopia. Adult onset myopia is usually low, but occasionally intermediate or high myopia cases are encountered. Adult onset myopia appears more frequently than evident from textbooks and literature on refractive distribution. A frequency estimate based on Danish material thus suggests that at least 25-30% of all adult age myopia is also of adult onset.