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고려대학교 산업시스템정보공학과장 인 창 , 박 동 현

Age-related decline in color perception and difficultiesWith daily activities-measurement, questionnaire, Optical and computer-graphics simulation studies

Keiko Ishihara et al.

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1. Introduction

Appearance of the Problem:

- 고령화에 따른 색체지각 능력의 감소로 인한 문제 발생 .

1) 노인들은 암 순응 (dark adaptation) 의 속도가 느려지고 그 수준이 감소 .

2) 수정체가 두꺼워지며 황색이 되어 청색광의 투과를 감소시킨다 (sanders and McCormick, 1993).

3) 그러므로 , 색깔을 고르거나 맞추는데 곤란을 겪으며 , 색상환 (hue circle) 의 다른 영역보다 청록색 및 적색 영역에서

오류가 많아진다 (Verriest, Vandeyvere, Vanderdonck and Boyce, 1981).

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1. Introduction (cont’d)

General Background:-Affected by Factors that…휘도 (luminance level), 대비 (contrast), 노출시간 (exposure Time), 과녁이동 (target movement), 연령 (age), 훈련 (training)

Goal: (Ultimate aim)suggest guideline for developing products for older adult.

(This study focused on…)Graphics to simulate vision in the elderly.

Transmittance less than 40% in elderly

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2. Method

2.1 visual difficulties of the elderly

1> optical simulation by young subjects-여학생 (18 세 ) 72 명을 대상으로 노란색의 필터안경을 쓰고 일 상 생활에서 어떠한 문제점이 있는지를 연구하였다 .

2> survey of elderly subjects- 사전 실험과 기존연구를 토대로 총 10 개의 Questionnaire를 만들었다 (p. 155). -subjects: 각기 다른 지역에 사는 60 세 이상 노인 1322( 남 : 584, 여 :738) 명- four grade(never, sometimes, often, always)

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Questions…Q1: Do you have trouble in reading small print?

Q2: Do you have trouble in seeing things because they appear hazy?

Q3: Does it take time to adjust to bright lights?

Q4: Does it take time to adjust to dim lighting?

Q5: Are you dazzled if lights shine into your eyes from the side?

Q6: Do you have trouble reading signs or identifying faces while walking?

Q7: Do you bump into people or things to your side?

Q8: Do you have difficulty telling whether the flame of a gas cooker is on or off?

Q9: Do you have trouble pouring the correct quantity of water or oil into a glass or pan?

Q10: Do you fail to notice a pedestrian traffic signal until it starts blinking?

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2. Method(cont’d)

2.2 Experiment on misjudgment of colors by the elderly-computer simulation was to simulate the color confusion identified

1> subjects: 남자 6 명 (80~86 세 ), 일상생활에 도움 없이 건강 .

2> Experimental design:-34 stimuli (2 set of 17 combinations) 를 제시-조도 : 440~460 Lx-자극제시시간 1s, 눈과 자극간의 거리 60~80cm-Without wearing glasses-Respond as “same” or “different colors”

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2. Method(cont’d)

2.2 Experiment on misjudgment of colors by the elderly

3> stimulus

-10 colored tags on a piece of gray paper as a stimulus

-8 distracters – 애매한 색상들의 사각형 tag 로 구성됨 (Y - GY - G).

-2 targets – 원 tag

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2. Method(cont’d)

2.3 computer-graphics simulating how the elderly see

- yellow filter 실험보다 정확하고 유연성 있는 기법을 실시하기위해 computer graphics 를 이용한 simulation 을 사용 .

- apparatus: colorimeter -L*(lightness), a*(green/red), b*(blue/yellow): CIE color model

- the simulation made a converted image: identical colorWhite-yellow

Blue-greenBlue-black

Purple-brown

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3. Result and discussion

3.1 Visual difficulties in daily activities of elderly

1> optical simulation by young subjects(Problems)

-appearance of the colors changed (red changed to pink)-difficult to discriminate between certain combinations of colors(blue and dark)-liquid objects were difficult to see(gas flame, pour oil)- depth perception failed- electronic displays were difficult to read

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3. Result and discussion(cont’d)

3.1 Visual difficulties in daily activities of elderly

2> survey of elderly subjects

Cluster/factor analysis (c.f. Rubin)

-Q1, Q2: focusing

-Q3~Q5: adaptation

-Q6: dynamic visual acuity

-Q7: distance

-Q8~Q10: yellowish vision

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3. Result and discussion(cont’d)

3.1 Visual difficulties in daily activities of elderly

2> survey of elderly subjects

-answers: often-always All questions are significant age effect (Χ2test;p<.01, Q5;p<.05)

3.2 Experiment on misjudgment of colors by the elderly- problematic color combinationsyellow/white,

blue/green, dark blue/black, purple/dark red

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3. Result and discussion(cont’d)

3.3 computer-graphics simulating how the elderly see

-computer-graphics simulation 을 이용하여 yellowed

Vision 을 가진 노인들이 구분할 수 없는 color 를 미리 파악할 수

있다 .

Before after(simulated)

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4. Conclusion

-노인들을 시각능력을 고려한 시각 디스플레이 설계의 guidelines(LCD, traffic sign, map etc.).

- guidelines 를 통해 safety 와 function 을 향상 .

- 노령자를 고려한 vision 설계는 모든 사람에게 이로운 것이다 (Sanders, McCormick, 1993).