Skiascopy : And Its Practical Application to the Study of Refraction
Skiascopy : And Its Practical Application to the Study of Refraction
The book Skiascopy : And Its Practical Application to the Study of Refraction was written by author Here you can read free online of Skiascopy : And Its Practical Application to the Study of Refraction book, rate and share your impressions in comments. If you don't know what to write, just answer the question: Why is Skiascopy : And Its Practical Application to the Study of Refraction a good or bad book?
Where can I read Skiascopy : And Its Practical Application to the Study of Refraction for free?
In our eReader you can find the full English version of the book. Read Skiascopy : And Its Practical Application to the Study of Refraction Online - link to read the book on full screen. Our eReader also allows you to upload and read Pdf, Txt, ePub and fb2 books. In the Mini eReder on the page below you can quickly view all pages of the book - Read Book Skiascopy : And Its Practical Application to the Study of Refraction
In our eReader you can find the full English version of the book. Read Skiascopy : And Its Practical Application to the Study of Refraction Online - link to read the book on full screen. Our eReader also allows you to upload and read Pdf, Txt, ePub and fb2 books. In the Mini eReder on the page below you can quickly view all pages of the book - Read Book Skiascopy : And Its Practical Application to the Study of Refraction
What reading level is Skiascopy : And Its Practical Application to the Study of Refraction book?
To quickly assess the difficulty of the text, read a short excerpt:
The first is to determine accurately the direction of the principal meridians by bringing out most distinctly this band-like appearance in the pupil, in- dicating the direction of one of these principal meridians ; the other being always, for regular astigmatism, at right angles thereto. The second thing to be done is to measure accurately the refraction in each of these principal merid- ians, testing them, of course, one at a time.
The test proceeds at first as for myopia or hyperopia in a non...-astigmatic eye, until a point of reversal is found.
Then it is discovered that this point of reversal is only for the movement of light and shadow in one direction, and does not hold for movements at right angles to that direc- tion. The observer has now brought his eye to one point of reversal where the band-like appearance can be best per- ceived. But, as he has been working with the original source of light in the position most favorable for the meas- THE BAND-LIKE APPEARANCE. 49 urement of hyperopia and myopia, the position that brings the immediate source of light as close as possible to the mirror (see Chapter III), he will probably see very little ap- pearance of the band in the pupil, even with the higher degrees of astigmatism.
What to read after Skiascopy : And Its Practical Application to the Study of Refraction?
You can find similar books in the "Read Also" column, or choose other free books by Edward Jackson to read onlineMoreLess
To quickly assess the difficulty of the text, read a short excerpt:
The first is to determine accurately the direction of the principal meridians by bringing out most distinctly this band-like appearance in the pupil, in- dicating the direction of one of these principal meridians ; the other being always, for regular astigmatism, at right angles thereto. The second thing to be done is to measure accurately the refraction in each of these principal merid- ians, testing them, of course, one at a time.
The test proceeds at first as for myopia or hyperopia in a non...-astigmatic eye, until a point of reversal is found.
Then it is discovered that this point of reversal is only for the movement of light and shadow in one direction, and does not hold for movements at right angles to that direc- tion. The observer has now brought his eye to one point of reversal where the band-like appearance can be best per- ceived. But, as he has been working with the original source of light in the position most favorable for the meas- THE BAND-LIKE APPEARANCE. 49 urement of hyperopia and myopia, the position that brings the immediate source of light as close as possible to the mirror (see Chapter III), he will probably see very little ap- pearance of the band in the pupil, even with the higher degrees of astigmatism.
What to read after Skiascopy : And Its Practical Application to the Study of Refraction?
You can find similar books in the "Read Also" column, or choose other free books by Edward Jackson to read onlineMoreLess
Write Review:
User Reviews: