Eyecare Library

Presbyopia is a universal condition associated with the aging eye's diminishing ability to focus on close objects. It is neither a disease nor a defect. People usually discover this trouble during their mid-forties, and can correct it with lenses adapted to their various needs. Although presbyopia is a natural condition that everyone has to face sooner or later, proper diagnosis, eye care, safety precautions and monitoring of the condition can give our eyes a new lease on life!

Spots, Floaters and Flashes

The spots, floaters and flashes we sometimes see in our line of vision are part of a natural process. While they may be bothersome at times, in most cases these shadows and "light shows" are not harmful. However, if there is a sudden increase in the number of spots and floaters, if light flashes continue or vision dims for too long, immediate medical attention is needed.

Astigmatism

Astigmatism is a common vision defect most often caused by an irregularly shaped cornea, which blurs distorts eyesight. Although some degree of astigmatism is found in most people, those with problematic, moderate or severe astigmatism should seek correction. Special prescription glasses and contact lenses can correct astigmatism. Laser or conventional surgery are now used, and new acrylic implants can be inserted to round out the cornea to eliminate astigmatism. However, these procedures are achieving varying degrees of success and their risks should be duly noted. Although astigmatism cannot be prevented, proper eyecare and monitoring of your condition will help you see clear!

Crossed-Eyes

Medical name: strabismus. Other names: eye misalignment, squint, wandering eyes, wall eyes.
In a person with "crossed-eyes", one or both eyes point in different directions because the muscles in and around one or both eyes are not working in a coordinated manner. Causes of this defect are diverse, but in all cases, crossed-eyes should be treated as soon as possible after diagnosis to avoid loss of vision.

Color Blindness

Color blindness is a vision defect in which colors are not seen normally. The various degrees of color blindness are caused by the state of the color receptors found at the back of the eye. While there is no cure for color blindness, personalised methods of color identification and visual aids can help color-blind people. Parents, employers and color-blind people themselves all have a role to play in ensuring that environments are as safe and user-friendly as possible.

Farsightedness

Medical names: hyperopia, hypermetropia. Other common name: longsightedness, long-sight.
Farsightedness is a common vision defect caused by the shape and length of the eye, and may be accentuated by environmental stresses. Farsighted people see distant objects clearly and close objects less clearly. Children with severe farsightedness are a high-risk category for developing crossed-eyes and lazy eye, and should be treated. In adults, problematic, moderate or severe farsightedness should be addressed. Special prescription glasses and contact lenses can correct farsightedness. Larger or incisional procedures are now being used with varying degrees of success to eliminate farsightedness. Orthokeratology and drug therapy are two temporary solutions that can control the symptoms of this defect. The risks associated with these treatments and interventions should be duly noted. Although farsightedness cannot be prevented, proper diagnosis, eyecare and monitoring of the condition will bring things back into focus.

Nearsightedness

Medical name: myopia. Other commnon names: shortsightedness, closesightedness. Nearsightedness is a common vision defect caused by the shape and length of the eye, and may be accentuated by environmental stresses. Nearsighted people can see close objects clearly and distant objects less clearly. Special prescription glasses and contact lenses can correct nearsightedness. Laser or incisional procedures are now being used with varying degrees of succes to eliminate nearsightedness. The risks associated with surgical interventions should be duly noted. Although nearsightedness cannot be prevented, proper diagnosis, eyecare and monitoring if the condition will bring things back into perspective.

Diseases and Treatments

The uvea is the middle layer (tunic) of the eye. It includes the iris, ciliary body, and the blood vessels that serve the retina. Any infection or inflammation of the uveal tunic is called uveitis. Uveitis is a condition that affects young people more commonly than other eye diseases.

Macular Degeneration

A degenerative disease that affects the central spot (macula) of the retina, which is responsible for central vision. Age-related macular degeneration is the most common cause of vision loss in people over 60. There are two types: wet and dry. Some people with wet macular degenration may be helped by laser surgery. The cause of this disease is unknown, but scientists are studying whether vitamin and mineral supplements can prevent or slow its development.

Chalazion

Medical names: meibomian gland lipogranuloma, maibomian cyst, tarsal cyst. Other name:eyelid cyst.
A chalazion is a bump caused by a blocked oil gland duct in the upper or lower eyelid. A combination of home treatments can resolve a chalazion. Homeopathic and surgical interventions may also be useful.

Styes

Medical names: external hordeolum, internal hordeolum, maibomian stye. Other names: eyelash stye, eyelid stye.
Styes are infections of the glands around the eyelashes and under the upper and lower eyelids that may be associated with stress or eye conditions. Eyelash styes are less painful and clear up with less effort than those found within the eyelid. Good hygiene and eyecare is key in healing any stye.

Dry Eye

People with dry eye have burning, gritty or tired eyes. Dry eye occurs when the eye is bathed by not enough or poor quality tears. Computer users and post-menopausal women are most often affected. Fortunately, this condition is often preventable and may easily be treated.

Retinitus Pigmentosa

Other names: RP, pigmentary retinopathy, night-blindness disease.
Retinitus Pigmentosa is a group of rare diseases affecting the retina. Symptoms progress from poor night vision to loss of peripheral vision and may include blindness in some people. There is no cure, but experimental treatments may slow its progression. Visual aids along with professional monitoring and support are essential aids to coping with symptoms.

Keratoconus

People with keratoconus develop an irregular, cone-shaped cornea - the clear window that covers the eye's iris and pupil. This change in the cornea's structure blurs vision and makes people more nearsighted over time. Changes usually begin in the late teens and early 20s, then progress for about 10 to 20 years. No one knows the cause, but keratoconus runs in families. Most people with keratoconus can wear rigid gas permeable (RGP) contact lenses to correct vision problems. About 10% of people must have a corneal tranplant to improve their vision. This operation is successful in more than 90% of people. After a transplant, about 60% of people must still wear RGP contact lenses to correct their vision.

Lazy Eye

Medical name: amblyopia.
Infants and children with lazy eye experience a loss or lack of development of vision, usually in one eye. Lazy eye is caused by the physical limitations of the eye and the effect these limitations can have on the nerves leading to the brain. The three types of conditions that can lead to lazy eye are crossed-eyes, defects in the focusing power of the eye, and damage or clouding caused by cataracts or other diseases. In the treatment of this disease, the younger a child is, the more effective correction of vision tends to be. Parents have a special responsibility in seeing that prescribed treatment is closely followed so their children can look forward to a lifetime of good vision!

Glaucoma

Untreated glaucoma commonly causes vision loss called "tunnel vision" and can lead to blindness. A common cause is high aqueous pressure within the front of the eyes. Glaucoma treatment, to be successful, should start as soon as the pressure and/or vision loss are detected, based on careful diagnosis. For most people with glaucoma, once the pressure reaches acceptable lower levels, nerve damage may slow or stop, but the damage is not reversed. Anyone who knows they are in a high-risk category is advised to have their eyes examined regularly.

Diabetic Retinopathy

Diabetic retinopathy is a retinal blood-vessel disease that affects people with diabetes. It may progress from early to advanced disease. At first, vision is unaffected. In later stages, new blood vessels and fibrous tissue grow on the retina, interfering with sight. If not promptly treated, vision loss may occur. Tight control of blood sugar levels may prevent or slow the progress of this disease. Laser surgery may help preserve vision in some people with advanced disease.

Prevention

The fatigue and pain of CVS shows up after long-term computer use and leads to physical stress including eyestrain. Not only with computers. Videogames require extreme focus at a short distance range, which brings forth the same effects as with CVS. Constant strain due to problems related to lighting, posture, and the physical placement of screen, keyboard, mouse and work material can cause CVS. The syndrome is preventable. An additional critical component of CVS is ultraviolet radiation emitted by computer screens. This UV "noise" can be avoided by a filter placed directly in front of the screen, by a low UV monitor or with appropriate eyewear.

Prevention in Perspective

The best way to protect vision is through good general health. A balanced diet includes all the essential nutrients needed by the eyes for each vision mechanism. Examination by a specialist is critical to identify eye problems. Safety and correction of vision defects complete the picture of a person who is alive to the world they see around them.

Frequently Asked Questions

Vision changes occur naturally as you age. When you reach your 40s, focusing at close range becomes difficult. This is a natural part of the aging process caused by a gradual hardening of the eye's chrystalline lens, reducing its ability to change shape and focus. This condition is called presbyopia.

What are progressive addition lenses and how do they differ from ordinary bifocals?

Progressive addition lenses feature a continuous, clear field of vision from distance, through the intermediate ranges, to near without the use of annoying bifocal lines. Bifocal lenses use very old technology. Abrupt and awkward changes between the distance and near prescriptions are separated by annoying lines.