As part of a proper Schoolvision assessment, there are 8 tests necessary to complete the child’s eye examination. With thanks to Geraint Griffiths, the founder of the schoolvision technique, in the current series of blog posts we have been describing each test separately through series of questions and answers.
Here is a list of the eight tests:
- Brock string
- Dynamic fixation
- Accommodation facility
- Measuring Muscle Balance
- Trial Frame Challenges
- Follow – up
Here below are the questions and answers on the CREST test.
Q: When doing the CREST test, I currently measure the reading speeds at least 3 times:
- As the child presents at high and low contrast
- Quite possibly with and without glasses
- With the new prescription/tint in place at high contrast
I don’t re-measure the speed at low contrast as I feel some tints can impair the visibility of the teal letters. Do you recommend measuring it a fourth time with the prescribed Rx/tint at low contrast?
A: I do very much the same as you. Once I’ve established the nature of the reading difficulty:
- Accommodation insufficiency (with associated amblyopia) or
- Convergence insufficiency (pattern glare) or
- Both (Accommodation / convergence insufficiency)
I tend to rely less on the low contrast typeface for future monitoring. This does risk missing out useful information although I think time can be a constraint. You may be able to add to our understanding taking this fourth measure. I don’t think we can assume that the teal font will always be read slower with the tint, if the tint improves contrast and reduces glare.