Snellen chart

A Snellen chart is an eye chart used by eye care professionals and others to measure visual acuity. Snellen charts are named after the Dutch ophthalmologist Hermann Snellen who developed the chart in 1862. Vision scientists now use a variation of this chart, designed by Ian Bailey and Jan Lovie (see "visual acuity").

         The traditional Snellen chart is printed with eleven lines of block letters. The first line consists of one very large letter, which may be one of several letters, for example E, H, or N. Subsequent rows have increasing numbers of letters that decrease in size. A person taking the test covers one eye from 20 ft. away, and reads aloud the letters of each row, beginning at the top. The smallest row that can be read accurately indicates the visual acuity in that eye.

        The symbols on an acuity chart are formally known as "optotypes". In the case of the traditional Snellen chart, the optotypes have the appearance of block letters, and are intended to be seen and read as letters. They are not, however, letters from any ordinary typographer's font. They have a particular, simple geometry in which:

• the thickness of the lines equals the thickness of the white spaces between lines and the thickness of the gap in the letter "C"
• the height and width of the optotype (letter) is five times the thickness of the line.

Only the ten Sloan letters C, D, E, F, L, N, O, P, T, Z are used in the traditional Snellen chart. The perception of five out of six letters (or similar ratio) is judged to be the Snellen fraction.

http://en.wikipedia.org/wiki/Snellen_chart

The Nature of Mental Health

Mental health 

- the three part definition of mental health by the National Association for Mental Health is as follows:

1. being comfortable with yourself
2. feeling good about your relationship with others
3. being able to meet the demands of life

How to express emotions in matured, healthful way as well as coping with the daily stresses are also included in the definition of mental health

Mental health describes the person's ability to perceive reality as it is, respond to life's challenges, and develop rational life strategies. The person's evaluations of himself and to others are based on realistic expectations.

The characteristics of a HEALTHY Person

Mental health begins with self-understanding and self-acceptance

Persons should possess the following characteristics of healthy mind to be mentally healthy individuals

1. They feel comfortable about themselves
 

THEY HAVE:
a. self-respect
b. satisfied from simple pleasures
c. not carried away by their emotions
d. neither underestimate nor overestimate their abilities
e. feel able to deal most situations come their way
f. accepts their own shortcomings

2.They feel right about other people

a. feel a sense of responsibility to their fellowmen

b. respect many differences they find in people

c. they feel that they are part of a group

d. able to give love and consider the interest of others

e. have personal relationships that are satisfying and lasting

3. They are able to meet the demands of life

a. accept responsibilities

b. welcome new experiences and new ideas

c. set realistic goals for themselves

d. do something about problems as they arrive

e. think for themselves and make own decisions

f. plan ahead but do not fear the future

The Mental Illness defined

a person with mental illness is characterized by the following
1. self-respect and self-esteem is low
2. cannot relate to others
3. cannot cope with personal problems
4. a deep nervousness and shyness
5. has difficulty to distinguish reality
6. has the tendency toward fantasy and imagination
7. inability to meet everyday challenges in life.


Answer the following questions

1. What is the 3-part definition of mental health by the National Association for Mental Health?
2. Enumerate and described the following characteristics of a person with a healthy mind to be a mentally healthy person