L 30 



IV. Observations relative to the near and distant Sight of different 

 Persons. By James Ware, Esq. F, R. S. 



Read November 19, 1812. 



1 H E fact that near sightedness most commonly commences 

 at an early period of life, and distant sightedness generally at 

 an advanced age, is universally admitted. Exceptions, how- 

 ever, to these rules so frequently occur, that I flatter" myself 

 a brief statement of some of the coincident circumstances, at- 

 tendant on these different imperfections in vision, may not be 

 found wholly undeserving the attention of the Royal Society. 

 Near sightedness usually comes on between the ages of ten 

 and eighteen. The discovery of it most commonly arises from 

 accident; and, at first, the inconvenience it occasions is so 

 little, that it is not improbable the imperfection would remain 

 altogether unnoticed, if a comparison were not instituted v;ith 

 the sight of others, or if the experiment were not made of 

 looking through a concave glass. Among persons in the in- 

 ferior stations of society, means are rarely resorted to for 

 correcting slight defects of this nature ; and, indeed, I have 

 reason to believe the imperfection in such people is not unfre- 

 quently overcome by the increased exertions that are made 

 by the eye to distinguish distant objects. This, however, is 

 not the case, in the present day, with persons in the higher 

 ranks of life. When these discover that their discernment of 

 distant objects is less quick or less correcCthan that of others. 



