one. refractive eye of the system by
aqueous corneal refractive lens vitreous of the four components of the media.
1. cornea: Drive level: 11 ~ 11.5mm in diameter down: 10 ~ 10.5mm
peripheral corneal thickness for: 1.1mm a little thin for the Central (CCT): 0.5 ~ 0.7mm
before the radius of curvature: 7.7mm after the radius of curvature: 6.8mm
refraction Rate: 1.376 transmission rate: 97%
refractive power is about: 43.05D eyes account for the total refractive power of 73%.
2. aqueous: deep in the central chamber of about 2mm. The water content of 0.1ml, after the aqueous content of 0.06ml. The refractive index of aqueous humor: 1.336.
3. lens: a diameter of about 10mm; thickness of 4mm. 1.406
refractive index for the radius of curvature: the former is 10 to -6 after refractive power to 16.00D ~ ~ 20.00D
4. Vitreous: vitreous is not a glass, which is similar to the glass eyes of the people of the same material, the colorless, transparent, semi-solid, positive Jelly, the main ingredient is water, accounting for the bulk of the vitreous around 99%. The vitreous in front of a concave, is able to accommodate the lens, vitreous known as Au. When he was young, the lens and vitreous body can better adhesion to close, gradually increase with age, the lens and vitreous of the adhesive has gradually deteriorated, so senile cataract surgery to separate them easily. Vitreous surrounded by a layer of high density material, known as the vitreous membrane, and is divided into two parts before and after: before and after the first ILM membrane. Glass is no blood vessels in the body, which required nutrition from aqueous humor and choroid, slow metabolism and therefore can not be renewable, if defect, the aqueous humor from space to fill. When the vitreous opacity occur for various reasons, look at things, it will feel if mosquito flying in front. In addition increases with age, or due to a high degree of myopia and other reasons, the semi-solid vitreous gel will be gradually turned into a liquid form called vitreous liquefaction.
the refractive index for the vitreous: 1.336
II. refractive optical system
constant axial length 24.387mm; refractive power of eyes (when stationary) 58.64D
1. axis (axis): the surface of the cornea through a central front The vertical line, the eye node. Roundabout point in the optical axis. The shaft behind the sclera and the intersection point of the posterior eye. Before and after the great distance that is axial length.
2. axis as: eye gaze outside through the nodes and the related connection.
3. Fixed: Eye outside the room watching with the point of connection. (Roundabout: eyeball located in orbit around a center of rotation, the center is located about simplifying the cornea after 13.5mm Department.) Brbrbr4. Simplified eyes: eyes or a model of simplicity, also known as eyes, is a simplification of the eye refraction system The image of the eye model.
Figure 1 simplify
eye on: FF ': before and after the focus, EE' two main points, NN 'two-node
: to simplify the eyes basis points, including the two main focus of FF', and a representative of the N-node EE 'average The number of corneal refractive surface.
5. angle (a angle): objects at both ends of the outside world in the eyes of nodes forming an angle of the premises.
6.Kappa angle: watching outside the eye and the cornea before a connection with the optical axis angle. Kappa angle perspective and clinically can be seen as more or less the same point of view. As the Kappa angle measurement is not easy, often with the optical axis as the axis of the corneal reflex points in between to form the perspective of data. The easiest way to monitor patients with light 33cm Department to observe the corneal reflex points, such as in the central cornea coincides with the optical axis, the Kappa angle 0; in the central cornea nasal (temporal), is for the (negative) Kappa Kok, the general often less than 5 °, more than 7 ° or so seems to be oblique.
objects AB's A point of light through the n nodes in a Focus on Service, B point of light through the n nodes in the focus b Department, the retina such as the true and inverted, and its size may be knowledge of the following formula: Figure
Based on the style , Object-based high 120 mm, 5280 mm away from the node, then the height of the retina such as AB nb / Bn = 120 × 15/5280 = 0.34 mm. This value and central retinal approximate diameter of the hollow.