Soft Contact Lens Fitting
Kastl corey dickson david w.
Soft contact lens fitting. Common lenses used to fit astigmatic corneas including gp lenses soft toric lenses and scleral lenses left to right respectively. One study caroline andré 2002 measured 200 right eye corneas and found an average hvid a surrogate marker for corneal diameter of 11 8mm with a range of 10 2mm to 13 0mm. Hence proper fitting of the contact lenses is important to make sure that there wont be any harm to the eye and visual health different types of contact lenses have different fitting procedures. Contact lens spectrum is the most respected source of clinical contact lens information for optometrists opticians and ophthalmologists.
Soft lens wrapping is forgiving and may mask the disparity between hvid and standard base curves which illustrates the inexactness of standard soft lens fitting methods. At present contact lenses have become the best alternative for glasses. Soft toric lenses for patients who have low to moderate astigmatism 0 50dc to 1 75dc soft toric contact lenses are often the lens of choice. A soft lens by its very nature of being soft.
Unstable contact lens rotation can be indicative of a loose fitting lens and thus the base curve diameter or prism of the custom soft contact lens may need to be altered to stabilize the lens. Soft contact lens fitting trial lens fitting regarded as essential by some allows the feel of a lens experience patient reaction is assessable needs to be performed in average illumination pupil size assessments made with the aid of good illumination low to moderate magnification now easier and safer disposable trial lenses15. For example if you are fitting a soft toric contact lens with a prescription of 2 00 1 25 45 and you find an scor of 1 00 0 50 60 you can insert a 3 00d sphere lens the combined sphere component a plano 1 25 45 lens the cylinder component and a plano 0 50 60 lens the over refraction into a trial frame and. One must assess lens movement on blink in.
With a loose fitting lens the converse will occur. Basics of soft contact lens fitting peter r. The most common types of contact lenses are soft spherical and soft toric and rigid gas permeable contact lenses. While this is often cited as a method for judging the lens fit the authors.
Each month it offers timely editorial on fitting overcoming complications utilizing new technologies gaining patient compliance and more written by contact lens practitioners for contact lens practitioners. With a steep fitting lens the mires will look blurred prior to a blink and clear post blink.