B4SC Visual screening - Data

Data analysed from B4 School Check vision screening referrals 1 March 2010 to 28 February 201

Demonstration of focused and defocused Kay Pictures optotypes (upper and lower left, respectively) compared with a reference Landolt C optotype (upper and lower right).

<p>The stroke width, nominal acuity and amount of defocus are equal in the Kay Pictures and Landolt C targets; however, Kay Picture optotypes, because of their construction principles, are at least twice the size of the Landolt C. Images were constructed in Adobe Photoshop CS6 v13 using the Lens Blur filter.</p

Testability of charts in a group of 17 children 4–9 years of age.

<p>Testability of charts in a group of 17 children 4–9 years of age.</p

Mean (± standard deviation) of VA measurements for adults (white) and children (light grey) in focused conditions and defocused (adults black and children dark grey) conditions.

<p>Mean (± standard deviation) of VA measurements for adults (white) and children (light grey) in focused conditions and defocused (adults black and children dark grey) conditions.</p