The motivational statement of the theme. Light, electromagnetic radiation from 400 to 760 nm (nanometer) capable of producing a visual sensation

Light, electromagnetic radiation from 400 to 760 nm (nanometer) capable of producing a visual sensation, is one of the most essential components of the environment. It has a specific effect on eyesight and a person’s ability to perceive light. Light gives more than 80% of information from the environment. It has a favourable effect on the human body, stimulates the person’s vital activity, promotes metabolic processes, work capacity and productivity, improves general well-being and mood.

Light makes the environment healthier, i.e. “Where the sun does not shine, the doctor often comes”. Inadequate, irrational lighting has a negative effect on the functioning of the visual analyzer. It increases its fatigability and that of the central nervous system. Bad lighting at a work place usually results in decreased work capacity and productivity of people and causes occupational traumatism.

The doctor should be able to estimate the risk of inadequate lighting for the health of the patients as well as to give recommendations on the arrangement of lighting in a doctor´ s office, operating room and in some other buildings (e.g. patient care institutions, educational establishments, houses, etc.).

The objective: to teach how to prognosticate visual malfunctions and decreased working capacity due to improper lighting; to learn the principles of arranging and monitoring natural and artificial lighting.

Students’ classroom activities

1. Examination and estimation of natural lighting/daylight in a classroom using the following indicators: light factor (LF), angle of incidence, aperture angle, daylight factor.

2. Calculation and evaluation of the artificial lighting level in a classroom on the basis of specific capacity.

3. Determination of the stability of distinct vision.

4. Drawing a conclusion about the conditions for the work of the visual analyzer in the classroom.

5. Case problems. The solutions of the case problems should be reported in writing (see table 1, appendix, page 95.)

6. Presenting and discussing individual students’ reports.

Students’ independent activities

1. Light & lighting. Hygienic importance of lighting.

2. Hygienic evaluation of isolation mode in living rooms, educational establishments and patient care institutions.

3. Hygienic evaluation of indoor natural lighting.

4. Hygienic evaluation of indoor artificial lighting.

5. Physiological methods of evaluating lighting sufficiency.

Plan of students’ independent activities

“_______” ________________200 ___

1. Estimation of indoor natural lighting

1.1.Intention of premises: _____________________________________________

1.2.Climate zone: _______________________________________________

1.3.Orientation of building: ______________________________________

1.4. Light factor:

Area of the window glass _____________m², number of windows___________,

total area of the window glass _______________m²;

Total area of the floor ______m², the ratio of the window opening area to the floor area

light factor for the explored room ______________.

Standard light factor in the given room _____________________.

1.5. Angle of incidence at which a light ray strikes the working area:

Horizontal distance from the workplace surface to the window (L) ____m, height of the window (H) _____m, H: L ratio (tg a)_____, angle of incidence ______ in degrees.

Standard angle of incidence in the given room _________.

1.6. Aperture angle:

Determination of the minor angle:

The distance from the lower edge of the window to the point on the window pane which corresponds to the roof projection of the opposite building (D) ______m;

The distance from the workplace surface to the window (L) _______m,

D: L ratio (tangent of an angle) _____, minor angle _______in degrees;

Determination of the aperture angle:

It can be calculated using the following equation:

Aperture angle = Angle of incidence – Minor angle _______in degrees.

Standard aperture angle in the given room ________in degrees.

1.7. Coefficient of natural lighting:

Lighting intensity at a distance of 1m from the wall (most distant from window openings)_____lx

Outdoor lighting from diffused light of the sky _____________lx

Daylight factor ______%.

Standard daylight factor (considering visual tasks performed in the given room) ________%.

1.8. The direction of the incidence of light on the workplace surface ______.

Conclusion: _______________________________________________

2. Estimation of indoor artificial lighting.

2.1. Light source _______________________________________ _____

2.2. Type of lamp (considering light flux propagation) _____________________

2.3. Calculation of artificial lighting level:

Number of lamps in a room ________, lamp power ________watt, total lamp power ________watt, total area of the floor _________m², lamp specific output ______watt/m², conversion factor _________, artificial lighting ________________________________________lx.

Hygienic norm of artificial lighting_________%

Conclusion: _______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

3.Stability of distinct vision:

total study time ____ sec., total of all time spans when a piece was quite clearly seen ___sec.

Stability of distinct vision _____%.

Conclusion: ___________________________________________________________________________________________________________________________________________________________________________________________

4.Situational problem № ___(type 1)

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5. Situational problem № ___(type 2)

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