Description
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Therapeutic
heavier cords
Product Description
- Make sure the background setting (including your clothing) is either evenly light gray or even dark colour to avoid patterns that could distract the infant. If the infant’s visual sphere is limited, the surrounding visual information does not affect the child. However, these children are often disturbed by even weak noises and uncomfortable or unusual body postures.
- Start with the coarsest grating. Show the infant the grating simultaneously with the gray stimulus. Then show every other grating in succession.
- If the infant responds to the 0.25 and the 1.0 cpcm grating, but not to the 4.0 cpcm grating, present the 2.0 cpcm grating. The threshold is found quickly before habituation occurs. If the infant or child seems to lose interest, show a face figure (#253100 paddle) or colourful toys to motivate the infant to respond again.
| Topic | Discription |
| Catagory | Pediatric Opthalmology |
| Material | While I couldn’t find a very detailed material composition (e.g. exact paper stock, lamination), these charts are generally printed on durable, foldable board / heavy cardstock / laminated material so they survive repeated use. |
| Test Distance | Recommended for use at 10 feet (≈3 meters). |
| Dimensions | Unfolded size: approx 17″ × 21″ (≈ 43 cm × 53.4 cm), Folded: about 17″ × 10.5″ (≈ 43 cm × 26.7 cm), Foldable for easy transport / storage |
| How to use for | Detects visual acuity in infants, children, and non-verbal |
| Logarithmic / Proportional Spacing & Size Range | The lines are proportionally spaced in logMAR / ETDRS format., Line sizes range from 20/200 (6/60) for the largest (top) line to 20/8 (6/2.4) for the smallest (bottom), On the reverse side (Massachusetts Visual Acuity Format) it has a “50% spaced rectangle” version with line sizes from about 20/100 to 20/8 (6/30 to 6/2.4) equivalent. |
| Purpose | Designed for screening or testing distance visual acuity in young children (starting age about 2½ to 3 years, Useful in vision therapy, pediatrics, schools, or clinics to assess recognition acuity, amblyopia detection, monitoring progress |
| Durability | While I couldn’t find a very detailed material composition (e.g. exact paper stock, lamination), these charts are generally printed on durable, foldable board / heavy cardstock / laminated material so they survive repeated use., The foldable design reduces wear during storage / transport |
| Unique Selling Proposition (USP) | Works without verbal responses, portable, clear contras |
| Number of Paddles | Four paddles total: three with stripes of different widths/densities, one with a uniform grey surfac |
| Acuity Level | Six stripe sizes: 0.25–8.0 cycles/cm. |
| Set | 4 paddles (3 striped, 1 solid grey |
| Size | About 8 inches (20 cm) diamete |
| Handle | Easy-to-hold for quick testing. |
| Limitations | Measures detection (not recognition) acuity; needs proper setup and lighting |
| Limitations / Practical Considerations | Requires adequate ambient lighting and correct setup (vertical, mounted at eye level) for accurate readings. (Standard for any acuity chart.) (From clinical manuals),Younger children (under ~30 months) may have lower cooperation, so results might be less reliable or require additional encouragement |
| Accuracy & Standards | The proportional spacing (ETDRS/logMAR) means consistent scaling of visual acuity steps. This gives more precise measurement than some older non-log spaced charts., It has been validated in research: e.g. studies comparing Lea symbols vs Landolt C, showing good applicability in young children and good sensitivity for amblyopia |
| Included Accessories / Supporting Materials | Includes response key and instructions, Some versions include flash cards |
| Mounting / Display Features | Has a hole for hanging on a wall |
| Optotype Design (LEA Symbols) | Consists of four symbols: a house, an apple, a circle, and a square. The symbols are “crowded” (i.e. surrounded by other symbols / adjacent symbols) to make the test more sensitive (especially for amblyopia). |
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