What is the Snellen equivalent of?

The Snellen acuity = Test distance (feet)/Letter size read (Snellen equivalent). For example, if the patient could read the 160 line at 1 meter, a 5′ equivalent, their acuity would be recorded as 5/160. 5/160 is equal to a Snellen acuity of 20/640.

What is a Jaeger 1 eye test?

The Jaeger chart is an eye chart used in testing near vision acuity. It is a card on which paragraphs of text are printed, with the text sizes increasing from 0.37 mm to 2.5 mm. This card is to be held by a patient at a fixed distance from the eye dependent on the J size being read.

What does J1+ mean on an eye exam?

The J1 paragraph on a Jaeger card is usually considered the near vision equivalent of 20/20 vision on a distance eye chart. On some Jaeger cards, the J1+ paragraph is the 20/20 equivalent.

What does SPH mean on an eye prescription?

Sphere (SPH) – The term “sphere” means that the correction for nearsightedness or farsightedness is spherical, equal in all meridians of the eye. This indicates the amount of lens power, measured in diopters (D), prescribed to correct nearsightedness or farsightedness.

Are there different eye charts?

5) There are different types of eye charts These include Snellen Chart, LogMAR Chart, Jaeger Chart, E Chart, and Landolt C Chart.

Are all Snellen charts the same?

The Snellen chart is the most widely used. Alternative types of eye charts include the logMAR chart, Landolt C, E chart, Lea test, Golovin–Sivtsev table, the Rosenbaum chart, and the Jaeger chart….Eye chart.

Snellen chart used for visual testing.
Uses Vision testing
Related items Snellen chart Landolt C Lea test logMAR chart

What are the different types of Snellen charts?

The four most common eye charts used are:

  1. SNELLEN. The original eye chart designed in the 1860’s by the Dutch eye doctor Hermann Snellen.
  2. TUMBLING E. This type of eye chart is used for children that are too small to read or adults with reading or speaking difficulties.
  4. ETDRS.

What does J1 mean on a Jaeger chart?

Jaeger Eye Charts. This chart consists of short blocks of text in various type sizes. The type scale ranges from J1 to J11 or larger, with J1 being the smallest type. J2 is considered the equivalent of 20/20 distance vision at the reading distance indicated on the card, which is usually 12 to 14 inches from your eyes.

What is a Jaeger eye chart?

A Jaeger eye chart contains several blocks of successively smaller text, generally ranging in size from J10 (large print) to J1 (very small print). The original Jaeger eye chart was developed in 1867 and contained seven paragraphs, each printed in a successively smaller font size.

How many rows are on a Snellen eye chart?

There are many variations of the Snellen eye chart, but in general they show 11 rows of capital letters. The top row typically contains just one letter (usually the letter ‘E’). The other rows contain letters that are progressively smaller in size, with more letters per line.

What is Snellen acuity?

The most familiar is the Snellen eye chart. Snellen acuity is given in terms of a Snellen fraction S, which is defined as Typical testing distances for the Snellen chart are 20 feet and 6 meters. If a subject can read a line at 20 feet and the “normal” observer can see the same line at 40 feet, then the subject has 20/40 Snellen acuity.