This human eye model is an educational model of the eye for studying anatomy and physiology in general secondary education institutions. With it students become acquainted with the structure of the eyeball, its main components and their function. The model is used in biology, anatomy and physiology lessons in classrooms of the natural science profile for demonstrations and practical work, under the guidance of a teacher; the recommended age of learners is from 10 years, that is pupils of grade 5 and above.
The model is a realistic copy of the eye of an adult human, enlarged 3 times compared with the natural size and mounted on a rotating base. It is divided by a sagittal section through the anterior and posterior poles, which makes the internal structure visible, and the separate components of the eye, the cornea, the iris, the lens and the vitreous body, are detachable and can be removed for closer study. The anteroposterior diameter of the eyeball is 7 cm, and the scale of the model makes it possible to distinguish its main structures and their colour coding from a distance of 5 metres from the last desk, while the small captions on the schematic poster and in the booklet are meant to be examined close up. The model is made of impact-resistant plastic with realistic colouring, the base is matt and rotating and the fastening to the base is free, allowing horizontal rotation. The structures shown are the cornea, the iris, the pupil, the lens, the vitreous body, the retina, the optic nerve and the blood vessels. The model needs no source of electric power. Operating conditions are the premises of an educational institution at an air temperature from +5 to +40 °C and relative humidity from 40 to 60 % without condensate. The service life is 5 years and the warranty period is 12 months from the date of sale.
The set includes the eye model on a rotating stand — 1 pc; the upper half of the eyeball wall, detachable — 1 pc; the lower half of the eyeball wall — 1 pc; the cornea — 1 pc; the iris, detachable — 1 pc; the lens, detachable — 1 pc; the vitreous body, detachable — 1 pc; the rotating base with the stand — 1 pc; a schematic poster with the designation of the structures of the eye — 1 pc; a booklet describing the anatomical structures and their functions — 1 pc; the passport with the warranty coupon — 1 pc; and individual packaging — 1 pc. All the detachable components are securely fixed and are removed safely without additional tools, and the detailed description of the structures of the eye in Ukrainian with recommendations for the teacher is part of the set. The model is ready for use without additional preparation.
In work the model is first turned so that the class clearly sees the external surface of the eye, the cornea, the sclera, the iris and the pupil, and rotating the base shows different angles of view. The upper half of the eyeball wall is then lifted off, which should come away without effort, and the internal structure becomes visible: the retina, the blood vessels and the nerve endings on the posterior wall, where the imprints of the retina, the optic nerve disc, the macula and the blood vessels can be pointed out. The detachable components, the iris, the lens and the vitreous body, are removed one by one and each is shown while its anatomical function and its position in the living eye are explained. At the end of the demonstration all the detachable components are carefully returned to their places and the upper half is checked to fit tightly against the lower one.
The model is made of durable materials but can break if it falls from a height, so it is handled carefully and is not dropped or subjected to strong impacts; detachable components are removed methodically, without sharp objects or excessive force, and are placed on a protected surface away from the edge of the table. When the base is rotated it must move freely and fingers must not become caught. The model is intended for demonstration purposes and does not come into direct contact with human organs; all components are wiped with a dry clean cloth, and for washing only warm water with a minimal amount of mild detergent is used, without immersing the model in water. Abrasive powders, sharp objects, solvents and alcohol are not used, since they damage the surface and the colouring. Once a month the integrity of all components is checked for microcracks and deformation and the rotating base is checked for smooth movement. The model is protected from prolonged direct sunlight, which causes the colouring to fade, and is stored in the original packaging or a specialised container in a dry room at a temperature from +5 °C to +40 °C and relative humidity that does not exceed 80 %, with the detachable components placed separately in a protected compartment of the packaging.
