Optometry or optometry is the examination of the structure of the eye with the aim of discovering defects and vision disorders and prescribing suitable lenses or other visual aids or prescribing exercises to improve eye deficiencies and problems. An optometrist is a person who examines and diagnoses the patient’s vision disorders by using some tools and devices, and after identifying the client’s vision disorders, prescribes vision aids such as glasses, lenses, or a series of exercises and movements. An eyepiece helps to improve the visual system of the patient. Also, the optometrist performs detailed eye examinations and, in case of a disorder or disease that requires other treatment, he refers the patient to doctors such as ophthalmologists, neurologists, internal medicine doctors, etc., and in addition The optometrist has the possibility to prescribe medical glasses to the patient, and after that the optometrist makes the glasses in full compliance with scientific principles and presents them to the patient.
Therefore, if a person feels a disorder or a problem in his eyes, he should first go to an optometrist , so that if he is suffering from refractive errors, eye aberrations, Diplopia, and other such cases, he will be treated by the optometrist. Otherwise, refer to other doctors and surgeons with the diagnosis of the optometrist.
All children should be examined from 6 months of age and from 6 months to 6 years of age, which is considered a critical age for the eyes, should visit an optometrist once a year in order to prevent and treat lazy eye.
What symptoms should be referred to an optometrist?
- When you have to be close to the TV or book to watch TV or read a book.
- Deviation of the eyes
- Narrowing the eyes or tilting the head in order to see better
- Excessive rubbing of the eyes while doing eye work
- Hypersensitivity to light
- Tears flowing from the eyes and abnormal burning of the eyes while reading, working on the computer and watching TV
- Headache and eye fatigue
- Feeling of pain in the eyes and their bloodiness
- Diplopia, not recognizing distances and losing lines
- Temporary or continuous blurring of vision
- Early eye fatigue and excessive blinking
Vision measurement tests in occupational examinations
Tests that are used to measure eyesight in employment examinations include visual acuity or acuity, depth vision, and color vision, which are explained below.
Acuity or visual acuity
Visual acuity is measured by the Snellen chart, which usually has the letter E on the page. This test is designed to measure near and far vision and finally the result of the test is presented to the client as a fraction. For example, the fraction 20/40 means that the smallest image that can be recognized by the client is 2 times the standard size, that is, the mentioned line can be recognized by a person with normal vision at a distance of 12 meters, while the client in question has the ability to read. It has the same line at a distance of 6 meters. Visual acuity is considered as one of the most basic indicators of vision health, but you should know that visual acuity or acuity evaluates only the central vision of a person and other cases that involve parts of the retina does not show. Therefore, visual acuity test is only one of the indicators of eye health and does not check the overall health of eyes and vision.
The eyes of all of us humans have the ability to recognize the distance between objects using binocular and monocular signs. Due to the different images received from each object by the eye, when these images are combined in the human brain, depth perception is obtained for humans.
Normal and natural eyes with color vision can distinguish millions of different colors, but only about 30 colors can be identified for correct judgment and recognition. Color recognition depends on the following factors and conditions:
- Retina matching mode
- Stimulated area of the retina
- Simultaneous contrast
- Continuous contrast
There are two forms of color vision disorder, acquired and congenital, and the congenital type is more common than the acquired type. This disorder is seen in 8% of men and 0.5% of women, but it is an acquired disorder due to work and exposure to substances such as mercury, organic solvents, choroid diseases, optic nerve.
Healthy and normal eyes in steady state have the ability to detect a visual stimulus in an area of 70 degrees from the bottom side, 60 degrees from the top side, 60 degrees from the nasal side (internal) and 95 degrees from the temporal side (external). The normal horizontal field of view is up to 190 degrees. The main causes and limiting factors of the human field of vision are glaucoma, cataract, retinal disorders and aging. The decrease in field of vision in the age range of 16 to 60 years is usually 3 to 3.5%, while it increases to 13% in the age of over 65 years. Most patients who suffer from peripheral vision and visual field disorders still have adequate central vision.
The position of optometry in occupational medicine
It is very important to check the condition and diagnose the condition of vision problems and disorders in order to maintain and improve occupational health. In many cases, any problem in the vision system can lead to irreparable accidents and also reduce and affect the quality of people’s work. For this reason, it is very important to evaluate the field of vision, measure vision, depth vision and color vision. Improving people’s vision will improve the quality of work and production, reduce accidents and, as a result, cost and absenteeism. Recording and entering details of vision during employment is for assessing problems after accidents or personal illnesses, which is very useful in paying blood money. Previous optometry and optometry, as well as work and employee optometry periodically, make people with incurable visual impairments to be placed in styles and positions that are used with their capabilities. Vision problems usually get worse with the passage of time, which periodic evaluation and vision examinations and their timely diagnosis lead to placement in appropriate job positions and ultimately improve the efficiency of the individual and the system.