EFFECTS OF STUDY ON THE EYESIGHT. 85 



lamp, while the schoolboy with his text-books is found somewhere in 

 the outer circle. 



Twilight-reading is much practised, and is especially pernicious 

 that is, prolonging the study or reading after daylight has begun to 

 decline. The change is so stealthy that, when the interest is excited, 

 and the mind absorbed, the growing darkness is unheeded or unob- 

 served, till serious mischief is done. 



A curious and interesting case of injury to the sight by study is 

 that of Prof. John Nott, late of Union College, Schenectady. Over 

 thirty years ago his sight was permanently destroyed for all literary 

 purposes, " by attempting," as he says in a recent letter to the writer 

 of this, " too much study without thought of the necessity of care for 

 the eyes." How many are following after him ! In the same letter 

 he thus describes his case as diagnosed by Dr. Alexander, of London, 

 who alone of all whom he consulted was able to afford him even tem- 

 porary and partial relief: "Thirty-six very small glands in the eyelids 

 make oil for the eye, the same as oil for your lamp. When these 

 glands become dry, reading is impossible, although in other respects 

 the eye may be perfect. This was my disease no oil was supplied to 

 the eye." He makes or implies this noteworthy suggestion, which is 

 hereby commended to authors, publishers, and school-boards: that a 

 brief and appropriate caution be conspicuously printed or pasted in 

 the front of every school and college text-booh, by authority of commis- 

 sioners, superintendent, trustees, or faculty. Something like the fol- 

 lowing would perhaps realize his idea : 



Caution". Reader, your eyesight is worth more to you than any 

 information you are likely to gain from this book, however valuable 

 that may be. You are therefore earnestly cautioned 



1. To be sure that you have sufficient light, and that your position 

 be such that you not only avoid the direct rays upon your eyes, but 

 that you also avoid the angle of reflection. In writing, the light 

 should be received over the left shoulder. 



2. That you avoid a stooping position and a forward inclination 

 of the head. Hold the boak up. Sit erect also when you write. 



3. That at brief intervals you rest the eyes by looking off and 

 away from the book for a few moments. 



And you are further cautioned to avoid as much as possible books 

 and papers printed in small type, and especially such as are poorly 

 printed ; also to avoid straining or overtaxing the sight in any way. 



Boys may need to be reminded of the great importance of thor- 

 oughly cleansing the eyes with soft, pure water both morning and 

 evening. ' 



To many readers it would no doubt be interesting to consider how 

 each of the practices and conditions we have pointed out as producing 



