To check the quality of Cheap Oakleys Radar Sunglasses Discount glasses, for ordinary consumers, there are several strong operational simple tests:
1, the test lens transparency and optical homogeneity: hand lens from the front 30 cm observe a far object from the lens, if the scene is clear, no distortion, and slowly no jumping moves, then the transparency of the lens and optical uniformity are better.
2, the test optical center displacement: On a large white cross with fine strokes, strokes should be clear and straight. Hand lens placed between the eye and the cross, with one stroke of the eye to observe the shape of a cross from the mirror if the mirror inside and outside of the stroke is not a line, you can move the lens, so that the cross with the outside mirror lens inside the cross stroke strokes in a line, then brush or a small fountain at the center point of the cross point of the lens, this point is the optical center. The latter two are to point out the optical center of the lens, the optical center is observed and compared with bilateral symmetry, and measure the distance between the centers of the pupil is consistent with the prescribed distance with a small ruler. If the lens bending crosses strokes, then there is a lens or optical density uneven stress problems.
3, measuring axial astigmatism lens: the lens rotates 30 cm above the cross pattern, visible lens cross appeared to move, to be inside and outside of the lens attached to the cross strokes graphic, graphics positively cross, this time the cylinder axis consistent and linear, then the Fake oakleys frogskins sunglasses cheap for sale lenses were repeatedly moved along a straight line, straight line which was observed when the lens moves and staggered out more in a straight line, this line is the astigmatic axis, moving straight alignment of the lens so that the inside and outside, where the axis of astigmatism in Scheme standard lens, the amount of the solution is then measured and the horizontal angle of the axial center of the lens, is axially degrees.
But also grasp of the key issues with glasses
1, optometry equipment to advanced technology to perfect, to ensure accurate optometry.
2, no advanced computer equipment optometry, optician equipment and professional technical personnel is difficult with a qualified glasses.
3,quality control store purchase channels that directly affect the glasses qualified and unqualified.
4, the face and the frame is close to (your different face).
5, glasses and do not forget to credit cards.
6, asked in detail about the knowledge about the Cheap Tiffany and Co Necklace Jewelry Outlet glasses, optometrists commanded according to what is generally not a problem.