How will bringing an object close to the eye (proximity to the object) help in low-vision patients?
This technique depends upon special magnifying spectacle lenses to see an object from very close. Moving close to an object to see it clearly is a normal human response. However an object can be taken only so close without blurring the image on the retina. As the object is brought closer a stronger lens (convex or plus lens) is needed to compensate for the insufficiency of the accommodation effort. Simultaneously, to relieve convergence, prisms are added on. This technique of magnification is thus known as relative distance magnification. Thus, the spectacle aids the normal accommodation, allowing the object to be viewed from very close, without discomfort, with a resultant enlarged retinal image. How do non-optical means help in low-vision patients? The object is seen large by the eye, without an optical magnifying aid. Thus, large printed letters in books and newspapers fall in this category. This method is known as linear magnification. A simple example would be a letter written in
