W m B n a s m u b – Check your eyesight! Can you make out these letters?
An ophthalmologist is a specialist who checks vision. A vision test is performed using special tables, where letters or symbols of various sizes are are printed in rows. The point of this diagnosis is to determine the patient's ability to distinguish details these letters/symbols at a near and far distance. Based on the data, a prescription that is issued by a physician and lenses for glasses or contact lens prescriptions are made.
We all have seen these at doctor’s offices. They are actually called "Tables Golovin-Sivtseva" in honor of the famous ophthalmologists who came up with this unique design. The tenth line from top (the starting point) confirms normal vision, and deviations from this line can tell you what your vision defects are. If you see the ninth line, your vision has index of 0.9 and so on.
What are the causes of visual defects?
If your ability to see has been reduced, you should get an eye exam to determine the cause cause of this decline. The most common refractive errors are separated into three types – myopia, hyperopia and astigmatism.
In the case of myopia, the image is not formed on the retina, but a little before it. Therefore the patient has trouble seeing objects that are far away, and can see without any difficulty things that are close. Myopia is corrected by "below zero" lenses, otherwise called "dispersing".
Hyperopia is a vision defect in which the image is formed behind the retina. In this case, the patient sees objects that are far away perfectly and has trouble seeing things that are close. For vision correction positive "collecting" lenses are used.
Astigmatism is a visual defect that is caused by an irregular shape of the cornea. Thenormal cornea has a spherical shape, while the defective one has a shape that resembles an egg, where one edge is slightly elongated relative to the center of the sphere. Astigmatic spectacle spectacle lenses are used to eliminate this defect and 'equalize the shape of the sphere of the cornea’ this is lens is referred to as a "cylinder".
Dr. Dello Russo not only diagnoses the type of refractive error, but also determines its value. And with this connection he assigns a particular way of correction with contact lenses or glasses, and sometimes by surgery.
Many vision problems are successfully solved because of the recent and growing progress of ophthalmology. One of the best things you can do for yourself is to make sure you see an eye doctor regularly to check your vision. You should go at least once a year so you don’t have anything to worry about. If an issue comes up, you will also be able to address it before it becomes too late.
If you have problems with vision, Dr. Dello Russo and his staff are ready to provide you with eye care at advanced levels. You can also ask us questions online through our website! We are glad to be here to help you!