مؤسسة الشرق الأوسط للنشر العلمي
عادةً ما يتم الرد في غضون خمس دقائق
this study has been Display what it got when tested VA for astigmatic, hyperopic and myopic patient with different charts (alphabets chart, E chart, Landolt Ring) -the result was surprising , the VA results for same eye has refractive error ,is difference when test by different charts(E, alphabets, landolt ring) the study will open the door for discussion this condition in the future by more research to know why It happen and what the best chart for VA Test. WHAT IS ASTIGMATISM? Astigmatism is when the cornea and/or lens is oval in shape, like an egg or a rugby ball instead of round, like a soccer ball A surface that is like that of a rugby ball or egg is called a toric surface A toric surface has a different curve in two directions (or meridians): one meridian is steeper (more curved), the other meridian is flatter (less curved) A toric surface causes light entering the eye to focus in two different places, rather than at one single point. WHAT WILL A PERSON WITH ASTIGMATISM COMPLAIN OF? People with astigmatism may complain of: – Eyestrain (sore, tired, red, dry, or watery eyes) – Headaches – Blurry vision at both distance and near. WHAT CAN WE DO FOR PEOPLE WITH ASTIGMATISM? Refraction (to determine the correct spectacle prescription they require) People with astigmatism can be given spectacles for clear distance and near vision to stop the headaches and eyestrain Because the two meridians of an astigmatic eye have different powers, the lens that is used to correct it must have different powers in each meridian This is called a cylindrical or astigmatic lens Ready-made spectacles use spherical lenses (not astigmatic lenses) and therefore will not be suitable for people with astigmatism