Visual Eyes Optometry

In visual eye optometry comprehensive eye examination is done. It deals with visions sharpness, eye and vision problems. Maintenance of good eye health is explained by visual eyes optometry.

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Ischaemic Optic Neuropathy Non Arteritic/NA-AION

Ischaemic optic neuropathy (ION) is the commonest adult optic nerve disorder encountered worldwide and can be expected to increase in incidence in our ageing population. In a recent review of 121 cases the mean age was 61 years. The condition has been classified as a) anterior (AION) affecting the optic nerve head and b) posterior (PION) involving that portion of the optic nerve behind its immediate retrolaminar portion.

Refractive Errors among Administrative Staff of Senior High Schools in the Kumasi Metropolis

Refractive error is a condition in which the eye in its relaxed state is unable to sharply see images due to failure of the optical system to bring parallel rays of light reflected off objects) of regard to a sharp focus on the retina. As a result, there is relatively poor vision as images of objects are seen to be blurred. There are different types of refractive errors and they include hyperopia, myopia, and astigmatism, with overlapping forms. Myopia and hyperopia are said to occur when the optical system of the eye brings parallel rays of light into focus in front and at the back of the fovea, respectively. Astigmatism on the other hand occurs when rays of light from different planes do not come to the same point on the fovea.

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Moving Toward Consensus Terminology in Ophthalmic Practice

The dual purposes of this review are to point out inherent problems in communication due to lack of consensus terminology, and to review preferred ophthalmic terms or to suggest others in order to improve eye care. With advances in informatics and the ongoing evolution of modern health care delivery, a common lexicon will also improve basic research and clinical outcomes. It is hoped that this paper will raise awareness of these issues and open profession-wide discussion with the ultimate goal of improving medical communication for ophthalmic patient care.

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Stereoscopic Memory When Stimuli No Longer Persist: Void and Binocular Intervals in Alternating Monocular Presentations

It was early realized by Exner in 1875 that stereopsis could occur when both eyes together receive the two images of a stereo pair one after the other. Stereopsis occurs even when a void interval is inserted between the presentations of each image.

For instance, Ogle found that stereopsis occurred when two 18 ms presentations were separated by a void interval of 100 ms. Stereopsis has also been studied with protocols in which the two images of a stereo pair were presented cyclically, in alternation to the two eyes. Guilloz - who was motivated by a practical interest in 3d X-ray radioscopy - produced cyclical presentations to the two eyes using a disk rotating in front of a stereoscope lenses. He also described how natural scenes are perceived through his apparatus.

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Interpupillary Distance Measurements among Students in the Kumasi Metropolis

The aim was to obtain interpupillary distance (IPD) measurements of students in the Kumasi Metropolis. The study will provide a database for manufacturers of spectacle frames and optical equipment with Ghana as the target population. The IPD is a crucial measure that needs to be considered before frames can be selected for patients who have been prescribed with spectacle corrections. IPD data from other populations are unsuitable due to variations with age, sex and race.

A cross-sectional study involving 500 students, aged 10 to 20 years and selected from Junior and Senior High Schools in the Kumasi Metropolis, was carried out. Interpupillary distances were measured using the pupillometer and the PD rule.

Results: Out of the 500 students, 290 (58%) were males. The study revealed that the distance and near IPD measured with pupillometer in students was 65.53 ± 3.348 mm and 61.60 ± 3.054 mm respectively. Furthermore, the IPD was 64.48 ± 3.429 mm and 62.01 ± 3.464 mm for distance and near, respectively, when measured with a PD rule.

Anterior Vitreous Incarceration after Phacoemulsification Cataract Extraction Imaged with Spectral-Domain Optical Coherence Tomography

Anterior vitreous incarceration is a condition in which vitreous prolapses into the anterior chamber and passes through a microscopic wound at an incisional site. The condition can be identified as a vitreous strand leading to the wound site during slit lamp examination. If the vitreous strand penetrates through all the corneal layers on to the extra ocular surface it becomes vitreous wick syndrome. Anterior segment imaging with spectral-domain optical coherence tomography of the iridocorneal angle can provide high definition scans to confirm vitreous incarceration and rule out vitreous wicking. It is important to appropriately diagnose this condition to prevent vision threatening complications.

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Vision-related Quality of Life in Children with Amblyopia

Vision plays an important role in most everyday activities. Consistent with this, people with visual impairment are usually faced with significant challenges in their daily activities. In children, such activities include playing, reading, socialisation and taking care of their daily needs. In the paediatric ophthalmological field, visual problems include high refractive errors, binocular disorders, depth perception deficiency, amblyopia and ocular pathology. These visual impairments in children potentially cause psychological and functional changes and could affect educational and social prospects and may thus impact on vision-related quality of life (VRQoL).

Amblyopia is usually defined as a unilateral or bilateral reduction in visual function caused by abnormal visual input resulting from degradation of the retinal image during a sensitive period of visual development, which historically has been thought to be the first seven years of life.

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Analysis on Visual Imaging Quality Affected by Human Eye’s Higher Order Aberration Measurement

In the 1990s, human eye’s wave front aberration measurement technology achieved rapid development. Williams DR etc. proposed two indirect wave front aberration measurement methods, namely, interferometry and double optical path methods. 

The former obtains human eye’s Modulation Transfer Function (MTF) by making use of interference that produces interference fringes with different aerial modulation degrees while the latter obtains MTF via irradiating ideal spherical wave into eye pupil, receiving wave-front information carrying aberration reflected from human eye via CCD (Charge Coupled Device), and analyzing its image.