The average decrease of CRT at the end of three months was 380um, a decrease of 179um (p<0.001) At the end of six months of our study, the average vision of our patients had improved to 85 ETDRS letters (corresponding to a vision of 20/40 on
Snellen chart).
For example, the smallest letter's size for system is 33 that is defined as Letter Category 9, so according to
Snellen Chart, the smallest letter's size is 20/20 ft/m that is the 1 means the users see perfectly, and the system gives message to users "You see perfectly!".
(23) In the Hong Kong study of chronic psychiatric patients, uncorrected DVI was defined as 20/40 or worse using the
Snellen chart. (5) Having calculated the frequency of uncorrected DVI in the current sample and using the same cutoff, the frequency of DVI rose to 35.7%, still lower than the 75% reported from Hong Kong.
The material resources used were: school classrooms, Illiterate E
Snellen Charts, tape measures, tissues (as eye patches), class lists and feedback forms--all readily available and inexpensive.
The subject maintained focus on a 6 x 6 matrix of 20/20 letters on the clinical, near, reduced
Snellen chart at 40 cm (2.5D).
I found that the amount of sphere needed to blur the Mizar-Alcor pair and the 20/20 line on the
Snellen chart was almost identical.
The mean visual acuity in patients with DME after 15 years was 0.31 in the
Snellen chart test and 1.26 in the Log-MAR test.
The screener used the
Snellen chart since Paul seemed to have good letter recognition and he scored 20/30 in his right eye and 20/20 in his left eye.
Screening procedures, location of screening, lighting, and distance from the
Snellen chart vary from school to school, and most schools do not comply with the standard.
The DVLA say this corresponds to a score of between 6/9 and 6/12 on a visual test known as the
Snellen chart.
Devised in 1863, the
Snellen chart is shaped like a pyramid with a large "E" at the apex with smaller and smaller lines of letters below.