Below you'll find a list of all posts that have been tagged as “Refraction”
In an earlier blog I described how OrthoK remodels the thickness profile of corneal epithelium – so what can this tell us about limits to refractive change that can be created? The average thickness of a person’s anterior corneal epithelium is 50µm, so if we are going to squish it we can’t squish it by more than 50µm (1µm = …
The amount of refractive correction that can be achieved by OrthoK has become such a contentious issue that it warrants more detailed explanation than I provided in my first blog on this topic. Welcome to the world of statistics – but don’t let this put you off, this is basic stats that you will be already familiar with in one way or …
When it comes to astigmatism, the research shows that approximately 40% of the initial astigmatism remains post treatment when using spherical OrthoK lenses.1 Following this research, -1.25DC is likely to end up at -0.50DC which, in most cases would be considered clinically acceptable. By the same conversion -1.50DC would give a predicted outcome of -0.60D, which, while not much different, is beginning to push …
Except for a few limits really anyone who is myopic and happy and able to wear contact lenses! Well, there are some limits to this rule to find the true key to success, but not many. Refraction Limits of refraction correction were covered in detail in an earlier blog where I made a case for accepting -4.50D with up to …