What types of refractive defects?
1. When the cornea curbs its normal range, the distant objects will appear unclear because they are concentrated in front of the retina, which is called short sightedness.
2. The long-sightedness of distant objects is obvious to people who suffer from long sight and close objects are not clear because the images here are concentrated behind the retina.
3. Astigmatism is the condition in which the degree of curvature of the cornea is uneven and the sight of distant and close objects becomes unclear.
4. Astigmatism leads to the presence of cornea, the shape of which is like the back of the spoon concave more in one direction and causes the concentration of light rays on more than one focal point.
1. When the cornea curbs its normal range, the distant objects will appear unclear because they are concentrated in front of the retina, which is called short sightedness.
2. The long-sightedness of distant objects is obvious to people who suffer from long sight and close objects are not clear because the images here are concentrated behind the retina.
3. Astigmatism is the condition in which the degree of curvature of the cornea is uneven and the sight of distant and close objects becomes unclear.
4. Astigmatism leads to the presence of cornea, the shape of which is like the back of the spoon concave more in one direction and causes the concentration of light rays on more than one focal point.