Indian Journal of Ophthalmology

ARTICLES
Year
: 1955  |  Volume : 3  |  Issue : 4  |  Page : 79--80

One lens for continuous sight for presbyopia and aphakia- A report of an accidental finding


Victor C Rambo 
 Christian Medical College, Vellore, India

Correspondence Address:
Victor C Rambo
Christian Medical College, Vellore
India




How to cite this article:
Rambo VC. One lens for continuous sight for presbyopia and aphakia- A report of an accidental finding.Indian J Ophthalmol 1955;3:79-80


How to cite this URL:
Rambo VC. One lens for continuous sight for presbyopia and aphakia- A report of an accidental finding. Indian J Ophthalmol [serial online] 1955 [cited 2024 Mar 29 ];3:79-80
Available from: https://journals.lww.com/ijo/pages/default.aspx/text.asp?1955/3/4/79/33585


Full Text

The trifocal lens is probably the world's best compromise lens for continuous vision distance to near for presbyopics and aphakics. It brings vision from the furthest horizon, it captures the arm length view and it makes the reading of small letters come to give their message to the reader's eyes and mind. Trifocal lenses are expensive, yet, for their utility and worth they are cheap. Advanced presby�opics and aphakics who live by using their eyes should get them, if they can afford them, or rather they cannot afford to be without them once the power needed for reading is at two and a half diopters, or more.

But there may be another way for continuous vision.

Mrs. R. S., a mission pharmacist and instructor of nurses, lost one eye many years ago. The one eye remaining became cataractous and had a successful operation. After a suitable time a prescription for distant glasses was given that gave her 6/5 vision. A prescription for an addition of plus three was given for near vision.

Three years later, Mrs. R. S. came for a "Check Up" of her prescription. She volunteered the information that she could at first afford to purchase but one pair of glasses, the distant lens. She said that she had not purchased the prescrip�tion for near glasses because she did not need them. She found out shortly after purchasing her distant lens, that she could read clearly as well as see distant objects clearly with the correction for distance prescribed.

I examined her one so called distant lens and found what would be ordinarily termed a poorly ground lens. The distant correction was correct according to prescription above and in. the centre but into the lower half of the lens a defect had been introduced by the gradual addition of an additional plus power. The lens had been ground so that the lower part of the lens wag fully plus two stronger powered than the centre and upper part of the lens. The cylindrical correction was maintained correctly throughout. The "defect" in the lens Mrs. R. S. was effectively and happily using for near work. Up to the strength of the plus two addition, Mrs. R. S. had been able to carry on her work in her need for a reading correction through the optical error of poor grinding.

The thought came to me and it is one I present to the profession that this so called "poorly ground" lens might be the very lens we want for our village and even other patients. Could not the Opticians deliberately grind lenses with the distant correction above and allow the grinding to leave a plus two and a half or three diopter additional below ? It might thus be possible for us to give our patients the benefit of "continuous vision" at an actually cheaper rate than it would take to produce a thoroughly "exact" lens.

Might it be possible that some of the patients who have been reported as having aphakia and still retaining accommodation of some sort might not have had just such a poorly ground lens as shown in Mrs. R. S.'s lens ?

Mrs. R. S. needed a moderate change in her distant prescription and a trifocal was prescribed to bring her vision to the beautiful continuous vision that such a lens can give.

But if the Optician can grind in her reading segment without using a trifocal or bifocal base, how good this would be! Perhaps the future will produce such a help for our presbyopics and aphakics.