Vision Associates

Perception and Developmental Assessment

 

LHR Lea Rectangles

go to price list

#A254600 LHR LEA Rectangles

is an educational plaything, derived from Effron's rectangles, and used to assess vision for perception of sizes. It follows the principle which suggests that the total area of the rectangles is constant. Luminance reflected from the surface cannot be used to perceive size differences, the differences in length must be seen. The task is to tell which of the two rectangles is the longer one. If need be, the rectangles can be studied using haptic and tactile information by feeling the rectangle that sticks out beyond the other one. The results of using the LEA Rectangles can indicate the possibility of having a specific loss of vision for size differences (ventril stream function) or loss of visual information to guide hand movement (parietal lobe).

 

LEA Mailbox

go to price list

#A254700 LHM LEA Mailbox

is used to assess visual perception of line orientation and has two components: 1) information for the hand movements in the parietal lobe and 2) picture perception in the infer-temporal lobe. To observe the first function the child is asked to drop a card through the slot of the LEA Mailbox. The child needs to demonstrate the perception of the orientation of the slot by turning the card in the correct position before it has moved half of the distance to the slot (dorsal stream function). A ventral stream function can be observed through interactive play using the LEA Mailbox. If a child cannot visually perceive the orientations of lines, drawing lines may be difficult & drawing angles will make no sense.

 

Heidi Expressions

go to price list

 

#A254500 Heidi Expressions

Developed by Lea Hyvärinen, MD to improve early evaluation of vision communication. Some visually impaired children cannot see expressions and do not recognize people's faces. Vision assessments should include testing ability to see differences in facial expressions. Consists of matching pairs of 6 expressions. A 3rd card of each of the 6 expressions has a bow in Heidi's hair. There are 3 sets of 18 cards at 100%, 10% and 2.5% contrst levels.