Question

2. Your grandfather has enjoyed very good vision for most of his 73 years. He still likes to read the newspaper to stay up to date on current events. You realize one day that he holds his paper at a distance of 13 inches from his face, which makes his arm tired after a while. You think he might benefit from some reading glasses. What condition is your grandpa mostly likely suffering from (in medically correct terminology)? 2a. What power of glasses should he look for? (Round to the nearest 0.25 power) (1) 2b. 3. You are designing software for a warehouse operation in Houston. Packers stand 5 feet away from a computer display that gives them a line of numbers for each order. Assuming they are licensed drivers in Texas with no restrictions, how tall should numbers and letters be on screen to assure legibility and thus minimize errors in filling orders? To assure legibility, it is recommended that you use a safety factor of 2x the minimum. Round to two decimal places. (2)

Answer 1

2.

Answer:

2. (a) Long sight (hypermetropia).

Description:

• The medical name for long-sight is hypermetropia, sometimes called hyperopia. Eyesight problems, such as hypermetropia, are also known as refractive errors.
• Long sight leads to problems with near vision and the eyes may commonly become tired. Distance vision (long sight) is, in the beginning, good.
• Long sight can be corrected by glasses or contact lenses, or sometimes 'cured' with laser eye surgery.

What are the symptoms of long sight (hypermetropia)?

• The main symptom is a difficulty with near vision. 'Tiring' of the eyes (asthenopia) is common and long-sighted people may have headaches and uncomfortable vision.
• There may be difficulties with seeing with both eyes (binocular vision), as the brain will tend to ignore signals coming from the most long-sighted eye. Lazy eye (amblyopia) or squint (strabismus) can therefore also occur in long sight.
• Long-sighted people may have difficulty with depth perception (3-dimensional vision), as this needs two eyes to work together, more or less equally.

What is the treatment for long sight (hypermetropia)?

Glasses

• The simplest, cheapest and safest way to correct long sight is with glasses. Convex prescription lenses (called plus lenses) are used to bend light rays slightly inwards to give a little bit of additional focusing power to the eye.
• The light rays then have a lesser angle to bend travelling through the cornea and lens and the lens has less work to do. As a result, the light rays are able to focus on the retina. There is an enormous choice of spectacle frames available, to suit all budgets; younger people may even regard them as a fashion accessory.

Contact lenses

• These do the same job as glasses but they sit right on the surface of the eye. Many different types of contact lenses are available. Lenses may be soft or rigid gas-permeable. They can be daily disposable, extended wear, monthly disposable, or non-disposable. Your optician can advise which type is most suitable for your eyes and your prescription.
• Contact lenses tend to be more expensive than glasses. They require more care and meticulous hygiene. They are more suitable for older teenagers and adults, rather than very young children.

Surgery

• Laser eye surgery is an option for some people with long sight. Generally, this type of surgery is not available on the NHS. Laser eye surgery is expensive but offers the chance to restore normal sight permanently. The procedure is generally painless.
• Complete and permanent resolution of the refractive error is possible in a number of people. Others have a significant improvement even though perfect vision is not achieved and glasses or contact lenses may still be needed.