Most spots are normal and are not a cause of blindness. But, sometimes, spots can be indications of more serious problems, and if you see them, you should have an optometric examination to determine the cause. Your optometrist uses these instruments to examine the health of the inside of your eyes and may also observe the spots within your eyes. For consistency, optometrists in the U.S. use 20 feet as the standard to express sharpness of vision. Other countries express visual acuity in their own way.
Visual acuity is affected by many factors.
Less than optimum clarity may result from vision conditions like nearsightedness, farsightedness, astigmatism, or from eye diseases. Some people can see well at a distance, but are unable to bring nearer objects into focus. Others can see items that are close, but cannot see those far away. This condition may be caused by nearsightedness. A comprehensive eye examination by Dr. s Dagostino and Hill should identify those causes, if any, that are affecting your ability to see well.