Overview of Common Vision Problems
- Myopia (Nearsightedness)
- Myopia is a type of refractive error in which the eye does not focus light properly onto the retinal surface to allow you to see images clearly. In myopia, close objects look clear but distant objects appear blurred. Myopia is a common condition that affects an estimated 25 percent of Americans. The prevalence is much higher among college students. It is an eye focusing disorder caused by a combination of genetic and environmental factors. It can be corrected by glasses or contact lenses.
- Hyperopia (Farsightedness)
- Hyperopia is a type of refractive error in which extra focusing effort is required to see distant and near objects clearly. Patients with hyperopia tend to have more eye fatigue, strain, and headache from prolonged reading because of the extra focusing effort required. It is caused by an eyeball that’s born too short or with curvatures that are too flat. Hyperopia can cause more severe symptoms in students with high reading demand. It can be corrected by glasses or contact lenses.
- Astigmatism is a refractive error resulting from the curvature of the cornea (the clear structure making up the front surface of your eye) not being born perfectly round on a microscopic level. Instead of looking like a perfectly round basketball shape, it has an oval shape like a football. It causes blurred images of both distant and near objects, particularly at night time. It can cause eye strain and headache when the patient tries to focus on small details for prolonged period of time. Astigmatism can be corrected by glasses and contact lenses.
- Amblyopia (lazy eye)
- Amblyopia is a condition in which vision is reduced but there is no pathology in the eye. It is caused by developmental problems of the visual pathway that connects the eye to the brain during early childhood. An eye turning in or out, uncorrected refractive errors, and any congenital eye conditions that interfere with clear focus of the eye can lead to amblyopia. If detected early in childhood, amblyopia can be treated by glasses, vision therapy, eye surgery, or a combination of these treatments. Unfortunately, there is very limited improvement from treatment of amblyopia detected in adulthood.
- Presbyopia is a common condition that almost everybody experiences with normal aging. It is caused by the progressive loss of elasticity in a structure inside the eye responsible for focusing at near distance called the crystalline lens. Symptoms include increased eye fatigue, headache, and difficulty focusing or maintaining focus when reading. The typical onset of symptoms is around late thirties to early forties. These symptoms can be relieved by reading glasses or multifocal contact lenses.
Contact lenses and eye health
There are two major types of contact lenses: soft lens and rigid gas permeable lens. Both types of contact lenses correct myopia, hyperopia, astigmatism, and presbyopia.
- Soft contact lenses are made with a soft, thin, and foldable plastic material. It is the most commonly used type of contact lens due to its easier fitting process and much faster adaptation by patients. Ninety percent of contact wearers today wear soft contact lenses. Soft contact lenses can correct near-sightedness, far-sightedness, astigmatism, and presbyopia. However, soft contact lenses provide less clear vision for patients with very high prescriptions as compared to rigid gas permeable lenses or glasses. Soft contact lenses can be worn as daily wear (during day time only) or extended wear (worn over night for one week to one month). The risk of infections and other ocular complications is significantly higher with extended wear. Daily wear soft contact lenses come in three major replacement types: daily disposable, biweekly, and monthly. Daily disposable lenses have been shown to be associated with the least ocular complications and provide the best comfort and convenience.
- Hard contact lenses are made with rigid and hard plastic, so it takes patients longer to adapt to the sensation from this type of lens. The advantages of hard contact lenses is its superiority in visual clarity in correcting patients with very high near-sightedness, far sightedness, and astigmatism. It is also the lens recommended for patients with eye diseases that cause corneal irregularity where glasses and soft contact lenses cannot provide good vision.
Proper contact lens wear and care:
- avoid over wear (especially overnight wear)
- replace lenses on time as recommended by your eye doctor
- replace lens cases every three months or as directed by the manufacturer of the cleaning solution
- rub and rinse contact lens case with disinfecting solution, then leave it to air dry
- have functional glasses to reduce dependence on contact lenses
- meticulous hand washing prior to handling contact lenses
- rub and rinse your lenses with fresh disinfecting solution prior to storage over night
- never reuse or top off contact lens solution; always toss out the old solution and replace with clean fresh solution
- avoid lens contact with tap or natural water; do not rinse lenses or cases with tap water
- do not use homemade saline solution or saliva to rinse lenses or cases
- remove contact lenses prior to showering, using a hot tub or swimming.
- remove contact lenses immediately when experiencing any redness or discomfort
- do not transfer contact lens solution to other containers for travel
- avoid touching the tip of the solution bottle to anything else
- see your optometrist for a yearly evaluation or sooner if any problems
Contact Lens Misuse
- Contact lens misuse behaviors include:
- wearing lenses for a longer period of time than recommended, especially sleeping with lenses over night
- not replacing lenses within the recommended period of time
- not cleaning lenses effectively or cleaning inappropriately
- not seeing an optometrist for a yearly evaluation
- ordering contact lenses online without a valid prescription
- Symptoms of eye complications from contact lens misuse include:
- chronic dryness
- persistent redness
- scratchy sensation
- light sensitivity
- blurry vision
- Most of the complications from improper contact lens wear and care resolve with discontinuation of the contact lenses and topical prescription eye medications. Some of these complications such as corneal defects or microbial keratitis can result in severe permanent vision loss. All of these complications can be avoided with proper contact lens wear and care.