Comparative Efficacy of Duochrome Test Verse +1 Blur Test in Detecting Refracting Error Across Different Ages

"The participant is seated at a standard testing distance (typically 6 meters or 20 feet). A duochrome chart with black letters on a split red-green background is presented.~After determining the subjective refraction, a +1.00 diopter (DS) lens is added to the final prescription. The participant is asked to read the distance visual acuity (VA) chart. The expectation is that the visual acuity should drop to 4 lines on Snellen chart (6/24) when the +1.00 DS lens is added. If VA reduces to 6/24: Indicates that the refraction is not over-minused or over-plussed (proper end point of refraction). If VA remains better than 6/24: Suggests the patient was still accommodating, possibly leading to over-minus (in myopes) or under-plus (in hyperopes) and the refraction should be re-evaluated."