Binocular vision is normal when both eyes are able to fuse images of the same object together without much effort when looking at both distance and near. When we switch from viewing a distant object to reading text on a page, our eyes converge in order to avoid double vision. When looking up, down, right or left at a distant object, both our eyes should move in the same direction to keep the images fused. They are four muscles in each eye that controls the eyes movement. These muscles are controlled by nerves. If a problem occurs in any of the nerves and/or any of the muscles it innovates, double vision may occur in some or all positions of gaze.
The Topograph is today an indispensable tool in any Hi Tech Eye Clinic, dealing with state-of-the-art customized contact lens design. It provides useful data of the shape and form of the corneal surface, including the presence of optical distortions.
The term refraction means to bend light. Your optometrist will use several methods to bend or change the direction of light coming from a distant object, to focus accurately on the retina by introducing different lenses before your eyes. When this is achieved, vision will be clearest. This results in the prescription for your spectacles or contact lenses. Refraction can only be accurate if the letter chart is at least 6 meters or 20 feet away from the patient. Any shorter, and the accuracy drops. To save space, most practitioners will use a mirror to double the distance.
What is Diabetic Retinopathy? Diabetic retinopathy is the leading cause of blindness in the world. If you are suffering from diabetes, it is important that your blood sugar level is controlled. You should also have a dilated eye exam by an ophthalmologist at least once a year.
Visual Field testing is an important diagnostic tool in the assessment of the eye’s visual fields. A normal visual field as measured from the central fixation point is 90 degrees temporally, 50 degrees nasally, 50 degrees superiorly and 60 degrees inferiorly. Many eye conditions can cause a narrowing of the field of vision, examples are Retinitis Pigmentosa, Glaucoma, etc. Other conditions for example Macular degeneration will only affect central vision. Even space occupying lesions, for example tumors in the brain may cause abnormal patterns in the visual fields.
Optical Coherence Tomography Analysis is much like Ultra-Sound, except that it uses light instead of sound This instrument is able to make 3-dimensional images of the Retina. The layers that make up the retina are easily visualized, the location of any abnormalities within the retina can then be identified. Eye conditions, for example Central Serous Retinopathy, Glaucoma may be diagnosed and monitored.
Glaucoma presents in many forms. Most common are open and closed angle Glaucoma. Intraocular Pressure (IOP) in excess of 21mmhg, is a sign that requires close monitoring. Observation of the optic nerves is a must during any eye examination as low IOP can also result in Glaucoma.
The Optos Daytona was designed to assist eye care professionals to diagnose and manage diseases of the retina. It produces a 200 degree image of the retina, wide enough to image almost all of the retina, without the need for dilation.